Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and 'Retourne la liste' does signal a read-only retrieval. It also usefully discloses provenance (service-public.gouv.fr, economie.gouv.fr, autoentrepreneurs.org), which builds trust in regulatory content. However, it says nothing about whether results are static/fixed, how they are structured, or how the conditional parameter affects the returned list.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.