Authorization must be enforced before restricted information enters model context. The retrieval service should authenticate the user, resolve role and document permissions, and filter candidate records before prompt construction. This prevents unauthorized content from appearing in prompts, model traces, cached context, tool results, or generated responses. A system-prompt instruction is behavioral guidance, not an enforceable access-control boundary. Post-generation filtering is also inadequate because the model has already received and processed the restricted data, creating exposure through output, logging, or indirect inference. Relying on general refusal behavior provides no deterministic authorization. The correct architecture treats RBAC as an application and data-layer control, with the model receiving only information the requesting principal is entitled to access.

Study Guide references/topics: Retrieval-layer RBAC; authorization before inference; least privilege; sensitive-context isolation.