Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds a useful behavioral detail that a PTR record may not exist ('if available'), implying a possible empty or null result. This adds value beyond the annotations, though it does not explain other edge cases (e.g., invalid IP formats).
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.