Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds useful provenance ('BLS data'), implying an authoritative external source and a monthly cadence, but says nothing about data lag, refresh timing, or return format. With annotations carrying the behavioral burden, this is a modest but real addition.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.