Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate a safe, read-only, idempotent operation. The description adds useful behavioral detail beyond the annotations: the schema is recursive, and some fields include a 'notes' string covering non-reflectable accepted keys. This helps the agent understand what the returned schema will contain.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.