Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, open-world behavior, so the safety profile is covered. The description adds context the annotations cannot: each call samples only 3 rotating root servers, so consecutive calls may return different observations, and the env-var dependency changes whether results are real probes or static reference data. Minor tension with idempotentHint, but that hint concerns side effects, not identical output, so it is not a contradiction.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.