Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, idempotentHint=true, and openWorldHint=true. The description adds useful behavioral context beyond annotations by specifying the data sources (EUR-Lex, OECD) and the nature of the return (warnings, citations, recommendations). It does not detail any side effects, but for a read-only simulator this is sufficient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.