An agent points at a remote MCP server, the connection fails, and the log says 401 Unauthorized — or 403 Forbidden . The reflex is to treat it like any other 401: something is broken, a token is wrong, fix the credential. Sometimes that is exactly right.
Source: [Dev.to](https://dev.to/merlonix/debugging-a-401-from-a-remote-mcp-server-1e8p)