A system prompt is a job description, not a manual
Every rule you add to the system prompt competes for attention with every other rule, and the model follows each of them a bit less. Keep the identity, the output format, and the three constraints that really matter.
Move procedures into skills or tool descriptions that load when they're relevant. If the prompt runs past a page, it's carrying documentation that belongs somewhere the model reads on demand.
ai-engineeringllm