Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so the safety profile is partly covered, but a false readOnlyHint on a polling tool is exactly the kind of thing that needs explanation. The description does add genuinely useful behavior the annotations cannot convey: the watch persists in the background and only advances while Claude Desktop is open. It stops short of saying what happens to accumulated history, how often checks actually fire, or that no version is captured while the app is closed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.