Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=false, so the description's 'without changing Typora' is largely redundant with structured data. It adds only marginal context ('explicit standalone renderer bridge') and says nothing about what constitutes a detected vs. absent bridge, or whether the check touches the filesystem or network.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.