Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of explaining behavior. It does clearly state the core mutating effect: the card's due date is removed. But it adds no context about permissions, reversibility, idempotency, or what happens if the card has no due date, which would make the behavior more transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.