Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish this as a safe read (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the bar is low. The description still adds two useful behavioral facts: results are 'public' details only, and returned URLs must be preserved exactly, which is a non-obvious output-handling constraint not encoded anywhere else.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.