Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the transparency burden. It clearly lists the transformations performed (removes quoted replies, signatures, mobile footers, tracking params, unsubscribe lines, invisible characters) and the outcome ('down to what was actually written'). However, it does not disclose any limitations or edge cases, such as behavior with non-text formats, but the explicit list provides solid transparency.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.