Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
readOnlyHint=true already tells the agent this is a safe read. "Examples use placeholders and do not execute actions" largely restates that safety profile, though it does usefully clarify the return content is illustrative rather than actionable. No detail on response size, formatting, or what a returned example looks like.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.