Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds valuable context beyond annotations by noting the tool uses the Shopify Storefront API and checks 'real-time stock status,' implying freshness of data. It does not describe return format or edge cases, but for a read-only check, the annotations plus real-time detail are sufficient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.