Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the description does not need to restate those. It adds valuable context beyond the annotations: pagination is explicit, results are scoped to 'owned' requests, and crucially, 'A request is not proof of payment'—which helps the agent avoid over-interpreting the returned data.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.