Start here. This is the direct spoken answer to practice first.
Overview
A managed guardrail can filter content or enforce selected policies, but it cannot understand every product invariant.
I use managed guardrails as one layer for supported content categories, denied topics, sensitive-data patterns, or policy checks. The application still authenticates users, authorizes data and tools, validates structured output, and controls side effects. Guardrail results are explicit outcomes that the user experience and telemetry can handle, not a guarantee that every unsafe or incorrect response is blocked.