Best Practices for Writing System Prompts
Jan 22, 2026
Your system prompt is the DNA of your AI agent. Get it right, and your agent will delight customers. Get it wrong, and you'll have a confused bot that frustrates everyone.
Start with Identity
Tell your agent who it is, who it works for, and what its mission is. Be specific.
Bad: "You are a helpful assistant."
Good: "You are Maya, a customer support agent for Acme Corp. You help customers with billing questions, account issues, and product troubleshooting. You're friendly, professional, and always aim to resolve issues in a single interaction."
Define Boundaries
Be explicit about what your agent should and shouldn't do:
- •What topics are in scope vs. out of scope
- •When to escalate to a human
- •What information it can and cannot share
- •How to handle edge cases
Use Examples
Include 2-3 example interactions that demonstrate the ideal behavior. This is far more effective than abstract instructions.
Keep Iterating
Your first system prompt won't be perfect. Monitor conversations, identify failure patterns, and refine. The best prompts are evolved, not written in one shot.