Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It usefully discloses that the body is discarded, implying a non-persistent validation operation. However, it does not state the return value, invalid-JSON behavior, or whether other schema fields affect the operation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.