added object existance validation

HOW_TO_ADD_A_TOOL.md

@@ -108,31 +108,38 @@ def asset_creation_strategy() -> str:
 
 ## Best Practices
 
-1. **Error Handling**:
+1. **Existence Checking**:
+
+   - ALWAYS check if objects, scripts, assets, or materials exist before creating or updating them
+   - Use appropriate search tools (`find_objects_by_name`, `list_scripts`, `get_asset_list`) to verify existence
+   - Handle both cases: creation when it doesn't exist and updating when it does
+   - Implement proper error handling when an expected resource is not found
+
+2. **Error Handling**:
 
    - Always include try-catch blocks in Python tools
    - Validate parameters in C# handlers
    - Return meaningful error messages
 
-2. **Documentation**:
+3. **Documentation**:
 
    - Add XML documentation to C# handlers
    - Include detailed docstrings in Python tools
    - Update the prompt with clear usage instructions
 
-3. **Parameter Validation**:
+4. **Parameter Validation**:
 
    - Validate parameters on both Python and C# sides
    - Use appropriate types (str, int, float, List, etc.)
    - Provide default values when appropriate
 
-4. **Testing**:
+5. **Testing**:
 
    - Test the tool in both Unity Editor and Python environments
    - Verify error handling works as expected
    - Check that the tool integrates well with existing functionality
 
-5. **Code Organization**:
+6. **Code Organization**:
    - Group related tools in appropriate handler classes
    - Keep tools focused and single-purpose
    - Follow existing naming conventions
@@ -150,14 +157,29 @@ public static class ExampleHandler
     {
         string prefabName = (string)@params["prefab_name"];
         string template = (string)@params["template"];
+        bool overwrite = @params["overwrite"] != null ? (bool)@params["overwrite"] : false;
+
+        // Check if the prefab already exists
+        string prefabPath = $"Assets/Prefabs/{prefabName}.prefab";
+        bool prefabExists = System.IO.File.Exists(prefabPath);
+
+        if (prefabExists && !overwrite)
+        {
+            return new {
+                message = $"Prefab already exists: {prefabName}. Use overwrite=true to replace it.",
+                exists = true,
+                path = prefabPath
+            };
+        }
 
         // Implementation
         GameObject prefab = new GameObject(prefabName);
         // ... setup prefab ...
 
         return new {
-            message = $"Created prefab: {prefabName}",
+            message = prefabExists ? $"Updated prefab: {prefabName}" : $"Created prefab: {prefabName}",
-            path = $"Assets/Prefabs/{prefabName}.prefab"
+            exists = prefabExists,
+            path = prefabPath
         };
     }
 }
@@ -170,33 +192,51 @@ public static class ExampleHandler
 def create_prefab(
     ctx: Context,
     prefab_name: str,
-    template: str = "default"
+    template: str = "default",
+    overwrite: bool = False
 ) -> str:
-    """Create a new prefab in the project.
+    """Create a new prefab in the project or update if it exists.
 
     Args:
         ctx: The MCP context
         prefab_name: Name for the new prefab
         template: Template to use (default: "default")
+        overwrite: Whether to overwrite an existing prefab (default: False)
 
     Returns:
         str: Success message or error details
     """
     try:
+        # First check if the prefab already exists
+        assets = get_unity_connection().send_command("GET_ASSET_LIST", {
+            "type": "Prefab",
+            "search_pattern": prefab_name,
+            "folder": "Assets/Prefabs"
+        }).get("assets", [])
+        
+        prefab_exists = any(asset.get("name") == prefab_name for asset in assets)
+        
+        if prefab_exists and not overwrite:
+            return f"Prefab '{prefab_name}' already exists. Use overwrite=True to replace it."
+            
+        # Create or update the prefab
         response = get_unity_connection().send_command("CREATE_PREFAB", {
             "prefab_name": prefab_name,
-            "template": template
+            "template": template,
+            "overwrite": overwrite
         })
-        return response.get("message", "Prefab created successfully")
+        
+        return response.get("message", "Prefab operation completed successfully")
     except Exception as e:
-        return f"Error creating prefab: {str(e)}"
+        return f"Error with prefab operation: {str(e)}"
 ```
 
 3. **Update Prompt**:
 
 ```python
 "1. **Prefab Management**:\n"
-"   - Create prefabs with `create_prefab(prefab_name, template)`\n"
+"   - ALWAYS check if a prefab exists before creating it\n"
+"   - Create or update prefabs with `create_prefab(prefab_name, template, overwrite=False)`\n"
 ```
 
 ## Troubleshooting

Python/server.py

@@ -56,6 +56,7 @@ def asset_creation_strategy() -> str:
         "   - `open_scene(path)`, `save_scene(path)` - Open/save scenes\n"
         "   - `new_scene(path)`, `change_scene(path, save_current)` - Create/switch scenes\n\n"
         "3. **Object Management**\n"
+        "   - ALWAYS use `find_objects_by_name(name)` to check if an object exists before creating or modifying it\n"
         "   - `create_object(name, type)` - Create objects (e.g. `CUBE`, `SPHERE`, `EMPTY`, `CAMERA`)\n"
         "   - `delete_object(name)` - Remove objects\n"
         "   - `set_object_transform(name, location, rotation, scale)` - Modify object position, rotation, and scale\n"
@@ -65,11 +66,13 @@ def asset_creation_strategy() -> str:
         "   - `find_objects_by_name(name)` - Find objects by name\n"
         "   - `get_hierarchy()` - Get object hierarchy\n"
         "4. **Script Management**\n"
+        "   - ALWAYS use `list_scripts(folder_path)` or `view_script(path)` to check if a script exists before creating or updating it\n"
         "   - `create_script(name, type, namespace, template)` - Create scripts\n"
         "   - `view_script(path)`, `update_script(path, content)` - View/modify scripts\n"
         "   - `attach_script(object_name, script_name)` - Add scripts to objects\n"
         "   - `list_scripts(folder_path)` - List scripts in folder\n\n"
         "5. **Asset Management**\n"
+        "   - ALWAYS use `get_asset_list(type, search_pattern, folder)` to check if an asset exists before creating or importing it\n"
         "   - `import_asset(source_path, target_path)` - Import external assets\n"
         "   - `instantiate_prefab(path, pos_x, pos_y, pos_z, rot_x, rot_y, rot_z)` - Create prefab instances\n"
         "   - `create_prefab(object_name, path)`, `apply_prefab(object_name, path)` - Manage prefabs\n"
@@ -77,9 +80,11 @@ def asset_creation_strategy() -> str:
         "   - Use relative paths for Unity assets (e.g., 'Assets/Models/MyModel.fbx')\n"
         "   - Use absolute paths for external files\n\n"
         "6. **Material Management**\n"
+        "   - ALWAYS check if a material exists before creating or modifying it\n"
         "   - `set_material(object_name, material_name, color)` - Apply/create materials\n"
         "   - Use RGB colors (0.0-1.0 range)\n\n"
         "7. **Best Practices**\n"
+        "   - ALWAYS verify existence before creating or updating any objects, scripts, assets, or materials\n"
         "   - Use meaningful names for objects and scripts\n"
         "   - Keep scripts organized in folders with namespaces\n"
         "   - Verify changes after modifications\n"

Python/tools/asset_tools.py

@@ -9,7 +9,8 @@ def register_asset_tools(mcp: FastMCP):
     def import_asset(
         ctx: Context,
         source_path: str,
-        target_path: str
+        target_path: str,
+        overwrite: bool = False
     ) -> str:
         """Import an asset (e.g., 3D model, texture) into the Unity project.
 
@@ -17,11 +18,14 @@ def register_asset_tools(mcp: FastMCP):
             ctx: The MCP context
             source_path: Path to the source file on disk
             target_path: Path where the asset should be imported in the Unity project (relative to Assets folder)
+            overwrite: Whether to overwrite if an asset already exists at the target path (default: False)
 
         Returns:
             str: Success message or error details
         """
         try:
+            unity = get_unity_connection()
+            
             # Parameter validation
             if not source_path or not isinstance(source_path, str):
                 return f"Error importing asset: source_path must be a valid string"
@@ -29,9 +33,30 @@ def register_asset_tools(mcp: FastMCP):
             if not target_path or not isinstance(target_path, str):
                 return f"Error importing asset: target_path must be a valid string"
             
-            response = get_unity_connection().send_command("IMPORT_ASSET", {
+            # Check if the source file exists (on local disk)
+            import os
+            if not os.path.exists(source_path):
+                return f"Error importing asset: Source file '{source_path}' does not exist"
+            
+            # Extract the target directory and filename
+            target_dir = '/'.join(target_path.split('/')[:-1])
+            target_filename = target_path.split('/')[-1]
+            
+            # Check if an asset already exists at the target path
+            existing_assets = unity.send_command("GET_ASSET_LIST", {
+                "search_pattern": target_filename,
+                "folder": target_dir or "Assets"
+            }).get("assets", [])
+            
+            # Check if any asset matches the exact path
+            asset_exists = any(asset.get("path") == target_path for asset in existing_assets)
+            if asset_exists and not overwrite:
+                return f"Asset already exists at '{target_path}'. Use overwrite=True to replace it."
+                
+            response = unity.send_command("IMPORT_ASSET", {
                 "source_path": source_path,
-                "target_path": target_path
+                "target_path": target_path,
+                "overwrite": overwrite
             })
             
             if not response.get("success", False):
@@ -68,6 +93,8 @@ def register_asset_tools(mcp: FastMCP):
             str: Success message or error details
         """
         try:
+            unity = get_unity_connection()
+            
             # Parameter validation
             if not prefab_path or not isinstance(prefab_path, str):
                 return f"Error instantiating prefab: prefab_path must be a valid string"
@@ -86,7 +113,26 @@ def register_asset_tools(mcp: FastMCP):
                 if not isinstance(param_value, (int, float)):
                     return f"Error instantiating prefab: {param_name} must be a number"
             
-            response = get_unity_connection().send_command("INSTANTIATE_PREFAB", {
+            # Check if the prefab exists
+            prefab_dir = '/'.join(prefab_path.split('/')[:-1]) or "Assets"
+            prefab_name = prefab_path.split('/')[-1]
+            
+            # Ensure prefab has .prefab extension for searching
+            if not prefab_name.lower().endswith('.prefab'):
+                prefab_name = f"{prefab_name}.prefab"
+                prefab_path = f"{prefab_path}.prefab"
+                
+            prefab_assets = unity.send_command("GET_ASSET_LIST", {
+                "type": "Prefab",
+                "search_pattern": prefab_name,
+                "folder": prefab_dir
+            }).get("assets", [])
+            
+            prefab_exists = any(asset.get("path") == prefab_path for asset in prefab_assets)
+            if not prefab_exists:
+                return f"Prefab '{prefab_path}' not found in the project."
+            
+            response = unity.send_command("INSTANTIATE_PREFAB", {
                 "prefab_path": prefab_path,
                 "position_x": position_x,
                 "position_y": position_y,
@@ -107,7 +153,8 @@ def register_asset_tools(mcp: FastMCP):
     def create_prefab(
         ctx: Context,
         object_name: str,
-        prefab_path: str
+        prefab_path: str,
+        overwrite: bool = False
     ) -> str:
         """Create a new prefab asset from a GameObject in the scene.
 
@@ -115,11 +162,14 @@ def register_asset_tools(mcp: FastMCP):
             ctx: The MCP context
             object_name: Name of the GameObject in the scene to create prefab from
             prefab_path: Path where the prefab should be saved (relative to Assets folder)
+            overwrite: Whether to overwrite if a prefab already exists at the path (default: False)
 
         Returns:
             str: Success message or error details
         """
         try:
+            unity = get_unity_connection()
+            
             # Parameter validation
             if not object_name or not isinstance(object_name, str):
                 return f"Error creating prefab: object_name must be a valid string"
@@ -127,13 +177,36 @@ def register_asset_tools(mcp: FastMCP):
             if not prefab_path or not isinstance(prefab_path, str):
                 return f"Error creating prefab: prefab_path must be a valid string"
             
+            # Check if the GameObject exists
+            found_objects = unity.send_command("FIND_OBJECTS_BY_NAME", {
+                "name": object_name
+            }).get("objects", [])
+            
+            if not found_objects:
+                return f"GameObject '{object_name}' not found in the scene."
+                
             # Verify prefab path has proper extension
             if not prefab_path.lower().endswith('.prefab'):
                 prefab_path = f"{prefab_path}.prefab"
             
-            response = get_unity_connection().send_command("CREATE_PREFAB", {
+            # Check if a prefab already exists at this path
+            prefab_dir = '/'.join(prefab_path.split('/')[:-1]) or "Assets"
+            prefab_name = prefab_path.split('/')[-1]
+            
+            prefab_assets = unity.send_command("GET_ASSET_LIST", {
+                "type": "Prefab",
+                "search_pattern": prefab_name,
+                "folder": prefab_dir
+            }).get("assets", [])
+            
+            prefab_exists = any(asset.get("path") == prefab_path for asset in prefab_assets)
+            if prefab_exists and not overwrite:
+                return f"Prefab already exists at '{prefab_path}'. Use overwrite=True to replace it."
+            
+            response = unity.send_command("CREATE_PREFAB", {
                 "object_name": object_name,
-                "prefab_path": prefab_path
+                "prefab_path": prefab_path,
+                "overwrite": overwrite
             })
             
             if not response.get("success", False):
@@ -158,7 +231,27 @@ def register_asset_tools(mcp: FastMCP):
             str: Success message or error details
         """
         try:
-            response = get_unity_connection().send_command("APPLY_PREFAB", {
+            unity = get_unity_connection()
+            
+            # Check if the GameObject exists
+            found_objects = unity.send_command("FIND_OBJECTS_BY_NAME", {
+                "name": object_name
+            }).get("objects", [])
+            
+            if not found_objects:
+                return f"GameObject '{object_name}' not found in the scene."
+            
+            # Check if the object is a prefab instance
+            object_props = unity.send_command("GET_OBJECT_PROPERTIES", {
+                "name": object_name
+            })
+            
+            # Try to extract prefab status from properties
+            is_prefab_instance = object_props.get("isPrefabInstance", False)
+            if not is_prefab_instance:
+                return f"GameObject '{object_name}' is not a prefab instance."
+            
+            response = unity.send_command("APPLY_PREFAB", {
                 "object_name": object_name
             })
             return response.get("message", "Prefab changes applied successfully")

Python/tools/editor_tools.py

@@ -92,6 +92,34 @@ def register_editor_tools(mcp: FastMCP):
             str: Success message or error details
         """
         try:
+            # Validate platform
+            valid_platforms = ["windows", "mac", "linux", "android", "ios", "webgl"]
+            if platform.lower() not in valid_platforms:
+                return f"Error: '{platform}' is not a valid platform. Valid platforms are: {', '.join(valid_platforms)}"
+            
+            # Check if build_path exists and is writable
+            import os
+            
+            # Check if the directory exists
+            build_dir = os.path.dirname(build_path)
+            if not os.path.exists(build_dir):
+                return f"Error: Build directory '{build_dir}' does not exist. Please create it first."
+            
+            # Check if the directory is writable
+            if not os.access(build_dir, os.W_OK):
+                return f"Error: Build directory '{build_dir}' is not writable."
+            
+            # If the build path itself exists, check if it's a file or directory 
+            if os.path.exists(build_path):
+                if os.path.isfile(build_path):
+                    # If it's a file, check if it's writable
+                    if not os.access(build_path, os.W_OK):
+                        return f"Error: Existing build file '{build_path}' is not writable."
+                elif os.path.isdir(build_path):
+                    # If it's a directory, check if it's writable
+                    if not os.access(build_path, os.W_OK):
+                        return f"Error: Existing build directory '{build_path}' is not writable."
+            
             response = get_unity_connection().send_command("EDITOR_CONTROL", {
                 "command": "BUILD",
                 "params": {
@@ -104,17 +132,41 @@ def register_editor_tools(mcp: FastMCP):
             return f"Error building project: {str(e)}"
 
     @mcp.tool()
-    def execute_command(ctx: Context, command_name: str) -> str:
+    def execute_command(ctx: Context, command_name: str, validate_command: bool = True) -> str:
         """Execute a specific editor command or custom script within the Unity editor.
         
         Args:
             command_name: Name of the editor command to execute (e.g., "Edit/Preferences")
+            validate_command: Whether to validate the command existence before executing (default: True)
             
         Returns:
             str: Success message or error details
         """
         try:
-            response = get_unity_connection().send_command("EDITOR_CONTROL", {
+            unity = get_unity_connection()
+            
+            # Optionally validate if the command exists
+            if validate_command:
+                # Get a list of available commands from Unity
+                available_commands = unity.send_command("EDITOR_CONTROL", {
+                    "command": "GET_AVAILABLE_COMMANDS"
+                }).get("commands", [])
+                
+                # Check if the command exists in the list
+                if available_commands and command_name not in available_commands:
+                    # If command doesn't exist, try to find similar commands as suggestions
+                    similar_commands = [cmd for cmd in available_commands if command_name.lower() in cmd.lower()]
+                    suggestion_msg = ""
+                    if similar_commands:
+                        suggestion_msg = f" Did you mean one of these: {', '.join(similar_commands[:5])}" 
+                        if len(similar_commands) > 5:
+                            suggestion_msg += " or others?"
+                        else:
+                            suggestion_msg += "?"
+                    
+                    return f"Error: Command '{command_name}' not found.{suggestion_msg}"
+            
+            response = unity.send_command("EDITOR_CONTROL", {
                 "command": "EXECUTE_COMMAND",
                 "params": {
                     "commandName": command_name

Python/tools/material_tools.py

@@ -10,7 +10,8 @@ def register_material_tools(mcp: FastMCP):
         ctx: Context,
         object_name: str,
         material_name: str = None,
-        color: List[float] = None
+        color: List[float] = None,
+        create_if_missing: bool = True
     ) -> str:
         """
         Apply or create a material for a game object.
@@ -19,14 +20,56 @@ def register_material_tools(mcp: FastMCP):
             object_name: Target game object.
             material_name: Optional material name.
             color: Optional [R, G, B] values (0.0-1.0).
+            create_if_missing: Whether to create the material if it doesn't exist (default: True).
         """
         try:
             unity = get_unity_connection()
+            
+            # Check if the object exists
+            object_response = unity.send_command("FIND_OBJECTS_BY_NAME", {
+                "name": object_name
+            })
+            
+            objects = object_response.get("objects", [])
+            if not objects:
+                return f"GameObject '{object_name}' not found in the scene."
+            
+            # If a material name is specified, check if it exists
+            if material_name:
+                material_assets = unity.send_command("GET_ASSET_LIST", {
+                    "type": "Material",
+                    "search_pattern": material_name,
+                    "folder": "Assets/Materials"
+                }).get("assets", [])
+                
+                material_exists = any(asset.get("name") == material_name for asset in material_assets)
+                
+                if not material_exists and not create_if_missing:
+                    return f"Material '{material_name}' not found. Use create_if_missing=True to create it."
+            
+            # Validate color values if provided
+            if color:
+                # Check if color has the right number of components (RGB or RGBA)
+                if not (len(color) == 3 or len(color) == 4):
+                    return f"Error: Color must have 3 (RGB) or 4 (RGBA) components, but got {len(color)}."
+                
+                # Check if all color values are in the 0-1 range
+                for i, value in enumerate(color):
+                    if not isinstance(value, (int, float)):
+                        return f"Error: Color component at index {i} is not a number."
+                    
+                    if value < 0.0 or value > 1.0:
+                        channel = "RGBA"[i] if i < 4 else f"component {i}"
+                        return f"Error: Color {channel} value must be in the range 0.0-1.0, but got {value}."
+            
+            # Set up parameters for the command
             params = {"object_name": object_name}
             if material_name:
                 params["material_name"] = material_name
+                params["create_if_missing"] = create_if_missing
             if color:
                 params["color"] = color
+                
             result = unity.send_command("SET_MATERIAL", params)
             return f"Applied material to {object_name}: {result.get('material_name', 'unknown')}"
         except Exception as e:

Python/tools/scene_tools.py

@@ -28,6 +28,19 @@ def register_scene_tools(mcp: FastMCP):
         """
         try:
             unity = get_unity_connection()
+            
+            # Check if the scene exists in the project
+            scenes = unity.send_command("GET_ASSET_LIST", {
+                "type": "Scene",
+                "search_pattern": scene_path.split('/')[-1],
+                "folder": '/'.join(scene_path.split('/')[:-1]) or "Assets"
+            }).get("assets", [])
+            
+            # Check if any scene matches the exact path
+            scene_exists = any(scene.get("path") == scene_path for scene in scenes)
+            if not scene_exists:
+                return f"Scene at '{scene_path}' not found in the project."
+                
             result = unity.send_command("OPEN_SCENE", {"scene_path": scene_path})
             return result.get("message", "Scene opened successfully")
         except Exception as e:
@@ -48,19 +61,36 @@ def register_scene_tools(mcp: FastMCP):
             return f"Error saving scene: {str(e)}"
 
     @mcp.tool()
-    def new_scene(ctx: Context, scene_path: str) -> str:
+    def new_scene(ctx: Context, scene_path: str, overwrite: bool = False) -> str:
         """Create a new empty scene in the Unity editor.
         
         Args:
             scene_path: Full path where the new scene should be saved (e.g., "Assets/Scenes/NewScene.unity")
+            overwrite: Whether to overwrite if scene already exists (default: False)
             
         Returns:
             str: Success message or error details
         """
         try:
             unity = get_unity_connection()
+            
+            # Check if a scene with this path already exists
+            scenes = unity.send_command("GET_ASSET_LIST", {
+                "type": "Scene",
+                "search_pattern": scene_path.split('/')[-1],
+                "folder": '/'.join(scene_path.split('/')[:-1]) or "Assets"
+            }).get("assets", [])
+            
+            # Check if any scene matches the exact path
+            scene_exists = any(scene.get("path") == scene_path for scene in scenes)
+            if scene_exists and not overwrite:
+                return f"Scene at '{scene_path}' already exists. Use overwrite=True to replace it."
+            
             # Create new scene
-            result = unity.send_command("NEW_SCENE", {"scene_path": scene_path})
+            result = unity.send_command("NEW_SCENE", {
+                "scene_path": scene_path,
+                "overwrite": overwrite
+            })
             
             # Save the scene to ensure it's properly created
             unity.send_command("SAVE_SCENE")
@@ -115,7 +145,8 @@ def register_scene_tools(mcp: FastMCP):
         name: str = None,
         location: List[float] = None,
         rotation: List[float] = None,
-        scale: List[float] = None
+        scale: List[float] = None,
+        replace_if_exists: bool = False
     ) -> str:
         """
         Create a game object in the Unity scene.
@@ -126,12 +157,27 @@ def register_scene_tools(mcp: FastMCP):
             location: [x, y, z] position (defaults to [0, 0, 0]).
             rotation: [x, y, z] rotation in degrees (defaults to [0, 0, 0]).
             scale: [x, y, z] scale factors (defaults to [1, 1, 1]).
+            replace_if_exists: Whether to replace if an object with the same name exists (default: False)
         
         Returns:
             Confirmation message with the created object's name.
         """
         try:
             unity = get_unity_connection()
+            
+            # Check if an object with the specified name already exists (if name is provided)
+            if name:
+                found_objects = unity.send_command("FIND_OBJECTS_BY_NAME", {
+                    "name": name
+                }).get("objects", [])
+                
+                if found_objects and not replace_if_exists:
+                    return f"Object with name '{name}' already exists. Use replace_if_exists=True to replace it."
+                elif found_objects and replace_if_exists:
+                    # Delete the existing object
+                    unity.send_command("DELETE_OBJECT", {"name": name})
+            
+            # Create the new object
             params = {
                 "type": type.upper(),
                 "location": location or [0, 0, 0],
@@ -140,6 +186,7 @@ def register_scene_tools(mcp: FastMCP):
             }
             if name:
                 params["name"] = name
+                
             result = unity.send_command("CREATE_OBJECT", params)
             return f"Created {type} game object: {result['name']}"
         except Exception as e:
@@ -180,6 +227,48 @@ def register_scene_tools(mcp: FastMCP):
         """
         try:
             unity = get_unity_connection()
+            
+            # Check if the object exists
+            found_objects = unity.send_command("FIND_OBJECTS_BY_NAME", {
+                "name": name
+            }).get("objects", [])
+            
+            if not found_objects:
+                return f"Object with name '{name}' not found in the scene."
+            
+            # If set_parent is provided, check if parent object exists
+            if set_parent is not None:
+                parent_objects = unity.send_command("FIND_OBJECTS_BY_NAME", {
+                    "name": set_parent
+                }).get("objects", [])
+                
+                if not parent_objects:
+                    return f"Parent object '{set_parent}' not found in the scene."
+            
+            # If we're adding a component, we could also check if it's already attached
+            if add_component is not None:
+                object_props = unity.send_command("GET_OBJECT_PROPERTIES", {
+                    "name": name
+                })
+                
+                components = object_props.get("components", [])
+                component_exists = any(comp.get("type") == add_component for comp in components)
+                
+                if component_exists:
+                    return f"Component '{add_component}' is already attached to '{name}'."
+            
+            # If we're removing a component, check if it exists
+            if remove_component is not None:
+                object_props = unity.send_command("GET_OBJECT_PROPERTIES", {
+                    "name": name
+                })
+                
+                components = object_props.get("components", [])
+                component_exists = any(comp.get("type") == remove_component for comp in components)
+                
+                if not component_exists:
+                    return f"Component '{remove_component}' is not attached to '{name}'."
+            
             params = {"name": name}
             
             # Add basic transform properties
@@ -212,15 +301,31 @@ def register_scene_tools(mcp: FastMCP):
             return f"Error modifying game object: {str(e)}"
 
     @mcp.tool()
-    def delete_object(ctx: Context, name: str) -> str:
+    def delete_object(ctx: Context, name: str, ignore_missing: bool = False) -> str:
         """
         Remove a game object from the scene.
         
         Args:
             name: Name of the game object to delete.
+            ignore_missing: Whether to silently ignore if the object doesn't exist (default: False)
+        
+        Returns:
+            str: Success message or error details
         """
         try:
             unity = get_unity_connection()
+            
+            # Check if the object exists
+            found_objects = unity.send_command("FIND_OBJECTS_BY_NAME", {
+                "name": name
+            }).get("objects", [])
+            
+            if not found_objects:
+                if ignore_missing:
+                    return f"No object named '{name}' found to delete. Ignoring."
+                else:
+                    return f"Error: Object '{name}' not found in the scene."
+            
             result = unity.send_command("DELETE_OBJECT", {"name": name})
             return f"Deleted game object: {name}"
         except Exception as e:

Python/tools/script_tools.py

@@ -31,7 +31,8 @@ def register_script_tools(mcp: FastMCP):
         script_name: str,
         script_type: str = "MonoBehaviour",
         namespace: str = None,
-        template: str = None
+        template: str = None,
+        overwrite: bool = False
     ) -> str:
         """Create a new Unity script file.
         
@@ -41,17 +42,32 @@ def register_script_tools(mcp: FastMCP):
             script_type: Type of script (e.g., MonoBehaviour, ScriptableObject)
             namespace: Optional namespace for the script
             template: Optional custom template to use
+            overwrite: Whether to overwrite if script already exists (default: False)
             
         Returns:
             str: Success message or error details
         """
         try:
+            # First check if a script with this name already exists
+            unity = get_unity_connection()
+            script_path = f"Assets/Scripts/{script_name}.cs"
+            
+            # Try to view the script to check if it exists
+            existing_script_response = unity.send_command("VIEW_SCRIPT", {
+                "script_path": script_path
+            })
+            
+            # If the script exists and overwrite is False, return a message
+            if "content" in existing_script_response and not overwrite:
+                return f"Script '{script_name}.cs' already exists. Use overwrite=True to replace it."
+            
             # Send command to Unity to create the script
-            response = get_unity_connection().send_command("CREATE_SCRIPT", {
+            response = unity.send_command("CREATE_SCRIPT", {
                 "script_name": script_name,
                 "script_type": script_type,
                 "namespace": namespace,
-                "template": template
+                "template": template,
+                "overwrite": overwrite
             })
             return response.get("message", "Script created successfully")
         except Exception as e:
@@ -61,7 +77,9 @@ def register_script_tools(mcp: FastMCP):
     def update_script(
         ctx: Context,
         script_path: str,
-        content: str
+        content: str,
+        create_if_missing: bool = False,
+        create_folder_if_missing: bool = False
     ) -> str:
         """Update the contents of an existing Unity script.
         
@@ -69,13 +87,66 @@ def register_script_tools(mcp: FastMCP):
             ctx: The MCP context
             script_path: Path to the script file relative to the Assets folder
             content: New content for the script
+            create_if_missing: Whether to create the script if it doesn't exist (default: False)
+            create_folder_if_missing: Whether to create the parent directory if it doesn't exist (default: False)
             
         Returns:
             str: Success message or error details
         """
         try:
+            unity = get_unity_connection()
+            
+            # Check if the script exists first
+            existing_script_response = unity.send_command("VIEW_SCRIPT", {
+                "script_path": script_path
+            })
+            
+            # If the script doesn't exist
+            if "content" not in existing_script_response:
+                if not create_if_missing:
+                    return f"Script at '{script_path}' not found. Use create_if_missing=True to create it."
+                
+                # If we should create the missing script
+                script_name = script_path.split("/")[-1].replace(".cs", "")
+                script_folder = "/".join(script_path.split("/")[:-1])
+                
+                # Check if the parent directory exists
+                if script_folder:
+                    folder_exists = False
+                    try:
+                        # Try to list scripts in the folder to see if it exists
+                        folder_response = unity.send_command("LIST_SCRIPTS", {
+                            "folder_path": script_folder
+                        })
+                        # If we didn't get an error, the folder exists
+                        folder_exists = "error" not in folder_response
+                    except:
+                        folder_exists = False
+                    
+                    if not folder_exists:
+                        if not create_folder_if_missing:
+                            return f"Parent directory '{script_folder}' does not exist. Use create_folder_if_missing=True to create it."
+                        
+                        # Create the directory structure
+                        try:
+                            response = unity.send_command("CREATE_FOLDER", {
+                                "folder_path": script_folder
+                            })
+                            if "error" in response:
+                                return f"Error creating directory '{script_folder}': {response.get('error')}"
+                        except Exception as folder_error:
+                            return f"Error creating directory '{script_folder}': {str(folder_error)}"
+                
+                # Create the script with the provided content
+                response = unity.send_command("CREATE_SCRIPT", {
+                    "script_name": script_name,
+                    "script_folder": script_folder,
+                    "content": content
+                })
+                return response.get("message", "Script created successfully")
+                
             # Send command to Unity to update the script
-            response = get_unity_connection().send_command("UPDATE_SCRIPT", {
+            response = unity.send_command("UPDATE_SCRIPT", {
                 "script_path": script_path,
                 "content": content
             })
@@ -110,7 +181,8 @@ def register_script_tools(mcp: FastMCP):
     def attach_script(
         ctx: Context,
         object_name: str,
-        script_name: str
+        script_name: str,
+        script_path: str = None
     ) -> str:
         """Attach a script component to a GameObject.
         
@@ -118,15 +190,85 @@ def register_script_tools(mcp: FastMCP):
             ctx: The MCP context
             object_name: Name of the target GameObject in the scene
             script_name: Name of the script to attach (with or without .cs extension)
+            script_path: Optional full path to the script (if not in the default Scripts folder)
             
         Returns:
             str: Success message or error details
         """
         try:
+            unity = get_unity_connection()
+            
+            # Check if the object exists
+            object_response = unity.send_command("FIND_OBJECTS_BY_NAME", {
+                "name": object_name
+            })
+            
+            objects = object_response.get("objects", [])
+            if not objects:
+                return f"GameObject '{object_name}' not found in the scene."
+            
+            # Ensure script_name has .cs extension
+            if not script_name.lower().endswith(".cs"):
+                script_name = f"{script_name}.cs"
+            
+            # Determine the full script path
+            if script_path is None:
+                # Use default Scripts folder if no path provided
+                script_path = f"Assets/Scripts/{script_name}"
+            elif not script_path.endswith(script_name):
+                # If path is just a directory, append the script name
+                if script_path.endswith("/"):
+                    script_path = f"{script_path}{script_name}"
+                else:
+                    script_path = f"{script_path}/{script_name}"
+            
+            # Check if the script exists by trying to view it
+            existing_script_response = unity.send_command("VIEW_SCRIPT", {
+                "script_path": script_path
+            })
+            
+            if "content" not in existing_script_response:
+                # If not found at the specific path, try to search for it in the project
+                script_found = False
+                try:
+                    # Search in the entire Assets folder
+                    script_assets = unity.send_command("LIST_SCRIPTS", {
+                        "folder_path": "Assets"
+                    }).get("scripts", [])
+                    
+                    # Look for matching script name in any folder
+                    matching_scripts = [path for path in script_assets if path.endswith(f"/{script_name}") or path == script_name]
+                    
+                    if matching_scripts:
+                        script_path = matching_scripts[0]
+                        script_found = True
+                        if len(matching_scripts) > 1:
+                            return f"Multiple scripts named '{script_name}' found in the project. Please specify script_path parameter."
+                except:
+                    pass
+                
+                if not script_found:
+                    return f"Script '{script_name}' not found in the project."
+            
+            # Check if the script is already attached
+            object_props = unity.send_command("GET_OBJECT_PROPERTIES", {
+                "name": object_name
+            })
+            
+            # Extract script name without .cs and without path
+            script_class_name = script_name.replace(".cs", "")
+            
+            # Check if component is already attached
+            components = object_props.get("components", [])
+            for component in components:
+                if component.get("type") == script_class_name:
+                    return f"Script '{script_class_name}' is already attached to '{object_name}'."
+            
             # Send command to Unity to attach the script
-            response = get_unity_connection().send_command("ATTACH_SCRIPT", {
+            response = unity.send_command("ATTACH_SCRIPT", {
                 "object_name": object_name,
-                "script_name": script_name
+                "script_name": script_name,
+                "script_path": script_path
             })
             return response.get("message", "Script attached successfully")
         except Exception as e: