Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, destructiveHint false and closed-world, so safety is covered. The description adds real context beyond them: it discloses the return shape ('step-by-step redesigned flow with friction removed and behavioral principles applied') and the cost ('20 credits (€0.20 per call)'), which an agent needs for budget decisions. It does not say whether the call fails on sparse input or how long a redesign takes, so it is not exhaustive.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.