mcp-builder

Use the FastMCP framework from the official MCP Python SDK. Define Pydantic models for input validation, register tools with the @mcp.tool decorator including annotations like readOnlyHint, and run the server over stdio or streamable HTTP transport.

Use the MCP TypeScript SDK's McpServer class and registerTool method with Zod schemas for input validation. Provide title, description, inputSchema, and annotations for each tool, then connect via StdioServerTransport for local use or StreamableHTTPServerTransport for remote deployment.

Use stdio for local integrations and command-line tools where the server runs as a subprocess of a single client. Use streamable HTTP for remote servers, web services, and scenarios requiring multiple simultaneous clients.

Create an XML evaluation file with 10 complex, read-only questions that have single verifiable answers, then run the evaluation.py script with your transport type. The harness connects to your server, runs each question through Claude, and reports accuracy, tool call counts, and per-task feedback.

A good tool description concisely states functionality, documents each parameter with constraints and examples, and specifies the return value schema. Include usage examples showing when to use the tool and when to use alternatives, plus expected error messages.

Evaluation answers must be verifiable by direct string comparison, so they cannot rely on dynamic state like current issue counts or member numbers. Base questions on historical, closed data such as completed projects or archived repositories so answers never change over time.