Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds that it returns per-deal rows with source quotes and accession URLs for verification, and that aggregate medians are not included here. This provides behavioral context about the output content and scope beyond what annotations state.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.