Asked about Parameters that change the output

What belongs in the system prompt rather than the user message?

An answer that works

Anything constant across the conversation: role, output format, tone, and the rule for what to do when information is missing. Keeping it stable also lets prompt caching apply to it.

Reading an answer is not being able to give one. The section that teaches this is Parameters that change the output, 2 hours of The Messages API.

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