Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: 'The current source supplies phrases but not per-phrase result counts,' which sets expectations about response content. Only minor gaps remain (e.g., no note on rate limits or suggestion source freshness).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.