Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations only declare readOnlyHint=false, leaving the safety profile undeclared. The description adds value by revealing this is a multi-action mutator that can also delete and activate/deactivate coupons, and that it supports batched writes. However, it doesn't disclose side effects, idempotency of retries, or whether batched execution is atomic — notable gaps for a tool that can trigger deletes.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.