Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden of disclosing behavior. 'Get details' implies a read-only operation, but it does not mention potential outcomes (e.g., error if group not found) or any side effects. For a simple retrieval, this is minimally adequate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.