Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the destructiveHint annotation, the description discloses that the operation mutates the library, is idempotent, and cascades by removing the paper from every collection. It also flags the auth requirement, giving full transparency about side effects.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.