Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly=true, destructive=false, openWorld=true, so the safety profile is covered. The description adds genuinely useful context beyond that: it draws on many data sources, takes 10-60 seconds (latency expectation), and requires an API key (auth prerequisite). It doesn't describe the shape of the returned answer, but for a read-only tool this is solid.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.