Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare destructiveHint=true, readOnlyHint=false, and idempotentHint=false, so the description's main contribution is the 'unpaid' guardrail and the 'after signed-in browser approval' precondition. It does not disclose consequences such as whether a payment hold is released or whether cancellation is irreversible, but the annotation baseline lowers the bar.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.