Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations (destructive, idempotent, openWorld), the description discloses the two-step safety pattern, that the preview is side-effect-free, that refunds go to the guest's card automatically, and a specific failure mode (refund_changed aborts the cancellation). It also covers the auth nuance around guest_email vs. agent token, which annotations do not convey.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.