Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description should disclose behavioral traits. It only says 'Fill multiple form fields at once,' lacking details on effects like overwriting existing values, validation, or whether the form is submitted. This is insufficient for an AI agent to predict outcomes.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.