Account Roles vs Database Roles

Claro has partnered with a third-party credit bureau that needs read access to the Claro database to validate score calculations. The bureau's team must not be able to see any other databases in Claro's account, and their access should be revocable cleanly when the contract ends. The data team is deciding whether to create an account role or a database role for this partner.

Which role type is most appropriate for this scenario, and why?