Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already indicate non-read-only and non-destructive nature. The description adds the requirement to provide base64-encoded data, which is useful but does not disclose other behavioral traits like file size limits, auth requirements, or return value. Partial transparency beyond schema and annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.