SEC MCP

# MCP Tool Development Guide ## Core Principles 1. Use SDK Transport 2. Keep Tools Simple 3. Let SDK Handle Complexity 4. Focus on Business Logic ## Quick Start ### 1. Server Setup from mcp.server.lowlevel import Server from mcp.server.sse import SseServerTransport app = Server("your-server-name") sse = SseServerTransport("/messages/") ### 2. Basic Tool Pattern @app.list_tools() async def list_tools() -> list[types.Tool]: return [ types.Tool( name="your_tool", description="What your tool does", inputSchema={ "type": "object", "properties": {}, "additionalProperties": False } ) ] @app.call_tool() async def handle_tool(name: str, arguments: dict) -> list[types.TextContent]: return [types.TextContent(type="text", text="Response")] ## Tool Development Steps ### 1. Define Purpose - What does the tool do? - What inputs does it need? - What output should it provide? ### 2. Create Schema - Start minimal - Add only required properties - Always set additionalProperties: false - Use clear property names ### 3. Implement Tool - Use async functions - Return TextContent - Keep error handling simple - Let SDK handle transport ### 4. Test Tool - Verify registration - Test basic functionality - Check error cases - Don't test transport layer ## Best Practices ### DO - Use SDK transport - Keep tools focused - Use simple schemas - Return TextContent - Let SDK handle errors ### DON'T - Implement manual SSE - Overcomplicate schemas - Handle transport manually - Create complex error objects ## Common Patterns ### Basic Tool async def your_tool() -> list[types.TextContent]: return [types.TextContent( type="text", text="Tool response" )] ### Tool with Parameters # In list_tools(): types.Tool( name="tool_with_params", description="Tool description", inputSchema={ "type": "object", "properties": { "param": { "type": "string", "description": "Parameter description" } }, "required": ["param"], "additionalProperties": False } ) ### Error Handling try: result = await do_something() return [types.TextContent(type="text", text=result)] except Exception as e: return [types.TextContent(type="text", text=f"Error: {str(e)}")] ## Testing Checklist ### Tool Registration - [ ] Tool appears in list_tools - [ ] Schema is correct - [ ] Description is clear ### Tool Execution - [ ] Works with valid input - [ ] Handles invalid input - [ ] Returns proper format - [ ] Error messages are helpful ## Remember 1. SDK handles transport 2. Keep tools simple 3. Focus on logic 4. Use TextContent 5. Simple error handling ## Resources - MCP SDK Documentation - Example Implementations - Tool Templates - Testing Guides