Choose a category, then a skill within it. Include an explicit no-match option and fall back when the result is uncertain.
Use a clear rating scale to reorder retrieved passages before sending a smaller selection to the language model.
Keep counting, arithmetic and date comparisons in code. Screening text for injected instructions is an extra probabilistic check, not a security boundary.
Worth knowing
Toy demonstrations with no runnable implementation linked in the publisher description. Speed, cost and test results are reported by the narrator and were not reproduced. The example injection cutoff does not establish safety.