Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile is covered. The description usefully adds that event copy is reference data and may not reflect live details, which is non-obvious context, but says nothing about result ordering, pagination, or how many results a broad query returns.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.