If I was me, I would start by giving a collection of LLMs the patent, ask half "why is this patent novel" and half "why is this patent not novel" and see what happens. I use this method of "debugging" my thinking (not code), might be a starting point here? Not sure.
LLMs are already good at summarizing the claims - patents all explain why they’re novel - so it would be a waste to ask them, especially if you reserve half the LLMs in your set for this question. Asking why a patent is not novel is a great question, but the problem with asking why they are not novel is it has to know all other patents (including very recently filed patents) and it has to be correct, which LLMs are not at all good at yet (plus they still tend to hallucinate confidently). This is a great test for LLM accuracy if you know the right answer already, and not a good test for patent validity.
