The Settings docstring and the installation docs claimed MCPServer could be
configured through MCP_* environment variables and a .env file, but MCPServer
always passes explicit constructor arguments to Settings, and those outrank the
environment in pydantic-settings, so e.g. MCP_DEBUG=true has never taken effect.
Make Settings a plain pydantic BaseModel and remove pydantic-settings from the
runtime dependencies (it moves to the dev group, where the examples still use
it). The migration guide explains how to feed environment variables into the
constructor for anyone who wants that behaviour.
Max Isbey