Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive and open-world. The description adds genuinely useful behavior — that the response is ranked, scored, explainable, and audited — but says nothing about the orchestration's cost/latency or what happens to the intermediate extraction/index artifacts, which matters most for a multi-stage tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.