Validation layer
Every booking should be validated before execution. The validation layer should check dates, cities, passenger identity, inventory, price, policies, payment readiness and cancellation rules.
Never let an agent book without explicit user confirmation.
Show price and cancellation rules before order creation.
Use webhooks as the source of truth after booking.
Safe agent design
Treat tool outputs as authoritative and model text as explanatory. If a tool says the order is not confirmed, do not let the agent claim it is confirmed.