Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds value by disclosing that the response includes lookupStatus, metrics, and age signals, which gives the agent expectations about the return structure. It does not go beyond annotations with details like rate limits or authentication, but given the simple read-only nature, this is sufficient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.