Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries full responsibility. It goes beyond a simple read operation by explaining that zeros are missing values that 'silently poison every average, minimum and range filter,' includes a real-world example, and instructs the agent on how to report findings. This is strong behavioral disclosure.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.