More clinical agents improve answers, not necessarily their reasoning
Multi-agent clinical systems can score better without becoming less likely to hallucinate, so clinicians should not treat a stronger final answer as proof of safer reasoning. The paper tests one single-LLM baseline and three multi-agent topologies across four models and three tasks, scoring both answers and rationales. In 36 comparisons, hallucination fell four times and rose eight times; the model, not the agent topology or count, determined the direction.