Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare read-only, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuinely new behavioral context, that results are 'scored deterministically with no model call' and that each hit carries method, path, summary, parameters, use-when/do-not-use guidance and an example query. That goes beyond the annotations, though it does not discuss result limits or empty-result behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.