System Prompt Structure

A system prompt is the most important piece of design in an AI product. It defines who the AI is, what it knows, how it behaves, and what it produces. It's the equivalent of a brand guide, interaction spec, and behavioral contract rolled into one document.

Anatomy of a System Prompt

A well-structured system prompt has distinct sections, each serving a specific purpose: 1. Identity and Role Who is the AI? What's its purpose? This anchors everything that follows.

• "You are a senior UX researcher helping design teams..."
• Keep it specific. "You are a helpful assistant" is too vague to produce consistent behavior. 2. Context and Knowledge What does the AI know? What's its domain? What information is it working with?
• Domain boundaries: what it's an expert in and what's outside its scope
• Background information relevant to the task
• User context: who it's talking to and what they need 3. Behavioral Rules How should the AI behave? What are the do's and don'ts?
• Tone and voice specifications
• Response format preferences
• Guardrails and prohibited behaviors
• Interaction style (ask clarifying questions, be concise, think step by step) 4. Output Specifications