Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the annotations (destructiveHint, idempotentHint), the description adds valuable behavioral context: the URL stops working for everyone, and the agent must confirm with the user before invoking. This significantly clarifies the impact and safety expectations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.