Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations, the description discloses concrete behavioral consequences: the attendee is emailed, the 24-hour reminder is re-armed, and a booking.rescheduled integration event fires. It also explains rejection conditions, which is valuable context for a mutating operation that is not marked destructive.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.