Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already mark the tool as read-only, idempotent, and non-destructive, so the safety profile is covered. The description adds useful behavioral context: it returns condensed, token-optimized data under 1.5 KB and lists the key fields included, which helps an agent understand response characteristics without needing to open the output schema.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.