Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral disclosure burden. It conveys a read-only list operation and the filtering behavior around 'available is true', which is useful. However, it does not mention response shape, edge cases, pagination, or explicitly state that it does not create a booking.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.