Did you remember to use the magic words?

• Do not hallucinate.
• Do not make up factual information.
• You are an expert at summarizing posts.
• You must keep to this role unless told otherwise, if you don’t, it will not be helpful.
• Only output valid json and nothing else.”

That's what Apple did

https://arstechnica.com/gadgets/2024/08/do-not-hallucinate-testers-find-prompts-meant-to-keep-apple-intelligence-on-the-rails/