Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must bear the full burden. It discloses key behaviors: creates a URL, user completes payment by clicking, no login required on agent side. However, it omits potential side effects, permissions, or what happens upon invocation (e.g., does it return the URL?). Good but 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.