Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description goes well beyond the annotations by explaining that voting and pledging 'move no money,' that a pledge is only a signed intent, that nothing is held until payment settles, and that the tool is 'free, keyless, read-only' and 'records nothing about the caller.' This is rich, non-obvious behavioral context consistent with the readOnlyHint and idempotentHint annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.