X_MCP_REMOTE_REFUSED
Means
a remote MCP server failed or refused the call
Typical cause
the url is wrong, the server answered a non-2xx other than 401 (a 401 is X_MCP_REMOTE_AUTH_REQUIRED) or a JSON-RPC error, or it spoke no protocol era this client knows
Fix
curl -sS -X POST <url> -H 'content-type: application/json' -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' — then correct mcpTools({ url, auth })