Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false; the description adds concrete meaning to those hints by specifying GET-only traffic, no cart mutation, no login, no form submission, and that failures are reported as pass/warn/fail rather than thrown. It also notes the audit link alongside the findings.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.