System prompt

The system prompt is the configuration text that precedes every conversation with an AI agent and that the user never sees: it says who you are (the Plumbing Martin assistant), how you speak (brief, warm, no jargon), what you can and cannot do (never quote off the price list), and when you escalate to a human.

For a business, the system prompt is policy, not a technical detail: it's where brand rules, prohibitions, and thresholds live. Well written, it makes the agent predictable; badly written, it manufactures unwanted behaviors — from the agent promising discounts to the one telling stories. The good practice is to version it like a company document: reviewed, approved, changed deliberately.