Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must fully convey behavioral traits. It states the action and output, but does not disclose side effects (e.g., whether the draft is modified), authentication needs, or rate limits. It is transparent about the return paths, but misses other behavioral context.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.