A colleague proposes decomposing every incoming question with the same general-purpose chain-of-thought prompt you’d use for any reasoning problem, skipping a schema check because ‘the model is good at this.’ What’s wrong with that, and what does it cost you?

Relying on a general-purpose prompt without schema validation allows the model to invent relations that do not exist in the graph. Because an empty result set from a hallucinated relation is indistinguishable from a missing fact, the generator is forced to guess. This defeats the purpose of GraphRAG, which is to ground answers in retrieved facts.