Add Guardrails So Your AI App Doesn't Lie — A Two-Layer Approach with NVIDIA NIM

In Part 1 we got a USC campus assistant talking. In Part 2 we taught it to retrieve only the relevant context. Both posts ended with the same observation - when someone asked for the wifi password, the assistant refused. That refusal worked because we told it to. It would have just as happily made something up if we'd phrased the prompt differently. This post is about hardening that refusal so it's not luck. Two guardrail layers, both small enough to read in one sitting, neither requiring a framework. First, tighten the prompt so the assistant knows what it's allowed to talk about.