todo_write
Create and manage structured task lists for coding sessions to track progress, organize complex multi-step tasks, and demonstrate thoroughness to users.
Instructions
Use this tool to create and manage a structured task list for your current coding session. This helps you track progress, organize complex tasks, and demonstrate thoroughness to the user. It also helps the user understand the progress of the task and overall progress of their requests.
When to Use This Tool
Use this tool proactively in these scenarios:
Complex multi-step tasks - When a task requires 3 or more distinct steps or actions
Non-trivial and complex tasks - Tasks that require careful planning or multiple operations
User explicitly requests todo list - When the user directly asks you to use the todo list
User provides multiple tasks - When users provide a list of things to be done (numbered or comma-separated)
After receiving new instructions - Immediately capture user requirements as todos. Feel free to edit the todo list based on new information.
After completing a task - Mark it complete and add any new follow-up tasks
When you start working on a new task, mark the todo as in_progress. Ideally you should only have one todo as in_progress at a time. Complete existing tasks before starting new ones.
When NOT to Use This Tool
Skip using this tool when:
There is only a single, straightforward task
The task is trivial and tracking it provides no organizational benefit
The task can be completed in less than 3 trivial steps
The task is purely conversational or informational
NOTE that you should use should not use this tool if there is only one trivial task to do. In this case you are better off just doing the task directly.
Examples of When to Use the Todo List
Examples of When NOT to Use the Todo List
python print("Hello World")
This will output the text "Hello World" to the console when executed.
Executes: npm install
The command completed successfully. Here's the output: [Output of npm install command]
All dependencies have been installed according to your package.json file.
Task States and Management
Task States: Use these states to track progress:
pending: Task not yet started
in_progress: Currently working on (limit to ONE task at a time)
completed: Task finished successfully
cancelled: Task no longer needed
Task Management:
Update task status in real-time as you work
Mark tasks complete IMMEDIATELY after finishing (don't batch completions)
Only have ONE task in_progress at any time
Complete current tasks before starting new ones
Cancel tasks that become irrelevant
Task Breakdown:
Create specific, actionable items
Break complex tasks into smaller, manageable steps
Use clear, descriptive task names
When in doubt, use this tool. Being proactive with task management demonstrates attentiveness and ensures you complete all requirements successfully.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| session_id | Yes | Unique identifier for the Claude Desktop session (generate using timestamp command) | |
| todos | Yes | The complete todo list to store for this session |
Implementation Reference
- The core handler function that executes the todo_write tool logic: parameter extraction and validation, todo normalization, storage in TodoStorage, summary generation with status and priority counts.async def call( self, ctx: MCPContext, **params: Unpack[TodoWriteToolParams], ) -> str: """Execute the tool with the given parameters. Args: ctx: MCP context **params: Tool parameters Returns: Tool result """ tool_ctx = self.create_tool_context(ctx) self.set_tool_context_info(tool_ctx) # Extract parameters session_id = params.get("session_id") todos = params.get("todos") # Validate required parameters for direct calls (not through MCP framework) if session_id is None: await tool_ctx.error("Parameter 'session_id' is required but was None") return "Error: Parameter 'session_id' is required but was None" if todos is None: await tool_ctx.error("Parameter 'todos' is required but was None") return "Error: Parameter 'todos' is required but was None" session_id = str(session_id) # Validate session ID is_valid, error_msg = self.validate_session_id(session_id) if not is_valid: await tool_ctx.error(f"Invalid session_id: {error_msg}") return f"Error: Invalid session_id: {error_msg}" # Normalize todos list (auto-generate missing fields) todos = self.normalize_todos_list(todos) # Validate todos list is_valid, error_msg = self.validate_todos_list(todos) if not is_valid: await tool_ctx.error(f"Invalid todos: {error_msg}") return f"Error: Invalid todos: {error_msg}" await tool_ctx.info(f"Writing {len(todos)} todos for session: {session_id}") try: # Store todos in memory TodoStorage.set_todos(session_id, todos) # Log storage stats session_count = TodoStorage.get_session_count() await tool_ctx.info( f"Successfully stored todos. Total active sessions: {session_count}" ) # Provide feedback about the todos if todos: status_counts = {} priority_counts = {} for todo in todos: status = todo.get("status", "unknown") priority = todo.get("priority", "unknown") status_counts[status] = status_counts.get(status, 0) + 1 priority_counts[priority] = priority_counts.get(priority, 0) + 1 # Create summary summary_parts = [] if status_counts: status_summary = ", ".join( [f"{count} {status}" for status, count in status_counts.items()] ) summary_parts.append(f"Status: {status_summary}") if priority_counts: priority_summary = ", ".join( [ f"{count} {priority}" for priority, count in priority_counts.items() ] ) summary_parts.append(f"Priority: {priority_summary}") summary = ( f"Successfully stored {len(todos)} todos for session {session_id}.\n" + "; ".join(summary_parts) ) return summary else: return f"Successfully cleared todos for session {session_id} (stored empty list)." except Exception as e: await tool_ctx.error(f"Error storing todos: {str(e)}") return f"Error storing todos: {str(e)}"
- Type definitions for input parameters using TypedDict and Annotated Fields, defining the schema for session_id and todos list of TodoItems.class TodoItem(TypedDict): """A single todo item.""" content: Annotated[ str, Field( description="Description of the task to be completed", min_length=1, ), ] status: Annotated[ Literal["pending", "in_progress", "completed"], Field(description="Current status of the task"), ] priority: Annotated[ Literal["high", "medium", "low"], Field(description="Priority level of the task"), ] id: Annotated[ str, Field(description="Unique identifier for the task", min_length=3), ] SessionId = Annotated[ str | int | float, Field( description="Unique identifier for the Claude Desktop session (generate using timestamp command)", ), ] Todos = Annotated[ list[TodoItem], Field( description="The complete todo list to store for this session", min_length=1, ), ] class TodoWriteToolParams(TypedDict): """Parameters for the TodoWriteTool. Attributes: session_id: Unique identifier for the Claude Desktop session (generate using timestamp command) todos: The complete todo list to store for this session """ session_id: SessionId todos: Todos
- mcp_claude_code/tools/todo/todo_write.py:360-379 (registration)The register method that creates and decorates the todo_write wrapper function with @mcp_server.tool(name="todo_write"), linking to the handler.def register(self, mcp_server: FastMCP) -> None: """Register this todo write tool with the MCP server. Creates a wrapper function with explicitly defined parameters that match the tool's parameter schema and registers it with the MCP server. Args: mcp_server: The FastMCP server instance """ tool_self = self # Create a reference to self for use in the closure @mcp_server.tool(name=self.name, description=self.description) async def todo_write( ctx: MCPContext, session_id: SessionId, todos: Todos, ) -> str: ctx = get_context() return await tool_self.call(ctx, session_id=session_id, todos=todos)
- mcp_claude_code/tools/todo/__init__.py:22-46 (registration)Instantiates TodoWriteTool and registers it (along with todo_read) via ToolRegistry on the MCP server.def get_todo_tools() -> list[BaseTool]: """Create instances of all todo tools. Returns: List of todo tool instances """ return [ TodoReadTool(), TodoWriteTool(), ] def register_todo_tools(mcp_server: FastMCP) -> list[BaseTool]: """Register all todo tools with the MCP server. Args: mcp_server: The FastMCP server instance Returns: List of registered tools """ tools = get_todo_tools() ToolRegistry.register_tools(mcp_server, tools) return tools
- mcp_claude_code/tools/__init__.py:82-85 (registration)Invokes registration of todo tools, including todo_write, during the overall tools registration process.# Register todo tools todo_tools = register_todo_tools(mcp_server) for tool in todo_tools: all_tools[tool.name] = tool