Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and clearly signals a read-only retrieval ('Get results'), but it does not disclose what the result payload looks like, whether it can fail, or whether it has side effects. The behavioral description is minimal but not misleading.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.