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 fully covered externally. The description adds one useful behavioral fact beyond that – the payloads are "fixed" (static/deterministic) rather than generated – but says nothing about return shape, size, or how many payloads come back.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.