Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The readOnlyHint annotation already indicates a safe non-destructive operation, so the bar is lower. The description adds 'clean Markdown' and 'extracting readable content,' which implies output quality, but does not disclose details about handling malformed HTML, lossy conversion, or preservation of specific elements. It provides some context beyond annotations but not rich behavioral detail.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.