xint-mcp-bearer-token-missing-causes-silent-connection-failure
The xint MCP server config had the URL present but no Authorization header, resulting in a silent ‘Failed to connect’ status — tools appeared registered but all calls failed. Always verify MCP configs include both the transport URL AND the required auth header (Authorization: Bearer <token>) in the headers block. The failure mode is silent because claude mcp list shows the server as registered even when auth is missing.