Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint/idempotentHint/destructiveHint=false, so the safety profile is covered. The description adds genuinely non-obvious behavioral context: it is a read-only entrypoint and does not incur paid research, and the query reaches sheets outside the initial page. The phrase "browse, search and edit" sits in mild tension with readOnlyHint, but the explicit "read-only entrypoint" clause resolves it.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.