Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, open-world, non-destructive, so the safety profile is fully covered. The description adds the per-zone walking behavior (DS/DNSKEY, algorithm usage at each level), which is useful context, but it says nothing about latency, number of network round trips, or cache behavior beyond what the force_refresh parameter implies.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.