Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so safety is covered. The description adds genuinely new behavioral facts: the result is only returned once the request is completed, and evidence URLs are temporary (expiring artifacts). It omits auth/credential implications of status_token and any error behavior for pending requests.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.