Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden and does add one useful detail: previously queued notifications still deliver. However, it does not explain the resulting watch state, permissions, reversibility, idempotency, or what happens to scans already in progress.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.