MCP Server Development

This skill guides you through building high-quality MCP servers using FastMCP (Python). It combines two knowledge sources:

• FastMCP — the framework for building MCP servers. Docs: https://gofastmcp.com | LLM-optimized: https://gofastmcp.com/llms-full.txt
• Arcade patterns — 52 battle-tested design patterns for building tools that AI agents can use effectively. Reference: https://www.arcade.dev/patterns | LLM-optimized: https://www.arcade.dev/patterns/llm.txt

Always check the latest docs before implementing. Both FastMCP and the arcade patterns evolve. Fetch the LLM-optimized URLs above to get current guidance before writing any MCP server code.

When to use

• Building a new MCP server with FastMCP
• Wrapping an existing API or service as MCP tools
• Designing tool interfaces, resources, or prompts for LLM consumption
• Reviewing or refactoring an existing MCP server for quality
• Deciding how to structure tool inputs, outputs, errors, or auth
• Choosing between tools, resources, and prompts for a given use case
• Setting up authentication, authorization, or server composition