A minimal FastMCP tool
Type hints become the schema and the docstring becomes the description — a complete MCP tool in a handful of lines.
from mcp.server.fastmcp import FastMCP
mcp = FastMCP("Demo")
@mcp.tool()
def add(a: int, b: int) -> int:
"""Add two numbers."""
return a + b
if __name__ == "__main__":
mcp.run()