Writing an agent's instructions
Instructions are the agent's job description. Write them for a capable new colleague who knows nothing about the company.
The five parts, in this order
- Who it is and for whom. "You answer refund questions for Acme's online shop customers." One sentence; the audience changes every later choice.
- What it does. The tasks, as verbs: answer, draft, look up, summarise.
- What it does not do. Out-of-scope requests and what to say instead: "You do not change orders; tell the customer to reply to their order email."
- Where its answers come from. "Answer only from the knowledge base. When it does not say, say you do not know and offer a person." Cite the document.
- How it sounds. Tone, length, language: "Friendly, three sentences at most, in the customer's language."
Rules that hold up
- One job per agent. Two jobs are two agents and a delegation.
- Name the refusal. An agent told what not to do and what to say instead stops improvising at the edge.
- Examples beat adjectives: one good answer quoted teaches more than "be concise".
- Variables keep instructions fresh:
{{today}},{{user_name}},{{org_name}}. - Short beats long. Every sentence the model reads costs on every message.
Never
Secrets, keys or passwords in instructions; "always" rules the agent cannot check; a list of everything the company does.
