This is a comprehensive guide for building Model Context Protocol servers that let LLMs interact with external APIs and services. It walks you through the full process: researching MCP design patterns, choosing between TypeScript and Python implementations, building tools with proper schemas and error handling, and creating evaluations to test if your server actually works. The guide emphasizes practical decisions like favoring comprehensive API coverage over workflow shortcuts, using streamable HTTP for remote servers, and writing actionable error messages. What stands out is the evaluation framework at the end, which pushes you to create 10 realistic test questions to verify your MCP server enables LLMs to solve real problems, not just call functions correctly.
npx skills add https://github.com/davila7/claude-code-templates --skill mcp-builder