Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations indicate readOnlyHint=true, openWorldHint=true, idempotentHint=true. Description adds context by naming data sources (World Bank LPI, live FX rate APIs) and output structure (risk indicators, exchange rates, supplier impact analysis), enhancing transparency beyond annotations alone.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.