The suggestion every RAG app ignores If you've shipped a retrieval-augmented assistant, you've written some version of this line in your system prompt: "If the answer isn't in the provided context, say you don't know. Do not make things up." And you've watched the model cheerfully ignore it under pressure. A confident-sounding question comes in, retrieval returns something adjacent , and the model stitches together an answer that's plausible, fluent, and wrong. Telling a language ...