Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds genuinely useful context the annotations cannot carry: the ~5-minute refresh cadence and the meaning of the four source states. However, it doesn't state whether incidents/advisories are always present, how far back incidents are reported, or the response's size/shape despite the include_ok toggle doing exactly that.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.