Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful domain-specific behavior beyond annotations: it clarifies that this is a free same-working-day dispatch for eligible UK orders, and that the response includes the order-by cutoff and promised dispatch date. It does not describe caching or update frequency, but that is a minor gap given the rich annotation coverage.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.