MCP Tool Definitions from Docstrings Only

Description

Writing MCP tool definitions by hand means keeping your schema in sync with your function signature every time something changes. Fast MCP eliminates that by generating the definition directly from the signature and docstring. What you just learned: Decorate any function with the MCP tool decorator Fast MCP infers parameter names, types, and descriptions automatically Claude Code receives an accurate tool definition without manual JSON Your docstring becomes the tool description the model reads at runtime Fast MCP handles MCP tool registration by treating Python function signatures as the source of truth for tool definitions. This approach removes schema drift and gives Claude Code reliable context about when and how to call each tool in your MCP server. #ai #aiagents #python #mcp #claudecode