Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds value by specifying what the overview contains (KPI counts, status breakdown, daily time series, recent activity), which is behavioral detail beyond the safety hints. It does not mention rate limits or data freshness, but the safety profile is covered.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.