Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds useful behavioral details beyond the annotations: it limits to public URLs, enforces 5 scans/minute, caches results for 24h, and returns a 0-100 score plus corrections. The readOnly and idempotent annotations already cover the safety profile.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.