Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Far exceeds what annotations convey (destructiveHint/idempotentHint are just hints). It enumerates exactly what is destroyed (page URL, image/video copy, shared script, shown request), states the action is irreversible and that re-sharing produces a new URL, clarifies job files survive, and specifies the authorization requirement plus the not_found outcome.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.