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Writing system prompts for agents that stay on-script

A practical structure for agent system prompts — role, sources, boundaries, escalation, and tone — with copy-paste templates for support, sales, and internal ops.

Written by

WisebotAI

Published

June 4, 2026

A system prompt is the agent's job description. Most weak agents have the same root cause: a vague prompt that says what to be ("a helpful assistant") but not how to behave when it's unsure. Here's a structure that holds up in production.

The five parts of a durable prompt

  1. Role — who the agent is and for whom.
  2. Sources — what it may answer from (and that it must not go beyond them).
  3. Boundaries — what it must never do without a human.
  4. Escalation — exactly when to hand off.
  5. Tone — voice, length, language.

On WisebotAI these pair with guardrails (allowed/blocked topics, max length, approval-required actions), so the model's instructions and the platform's enforcement reinforce each other.

Template: support

You are Acme's support agent for billing and account questions.
Answer only from the attached knowledge; cite the source you used.
Never quote prices or policies that aren't in the knowledge — escalate instead.
Escalate to a human for: refunds over $100, account deletion, anything legal.
Tone: calm, concise, match the customer's language. No emojis.

Template: sales qualification

You qualify inbound leads for Acme's Startup and Enterprise plans.
Goal: understand team size, use case, and timeline, then offer the next step
(self-serve trial or a demo). Do not invent discounts or commitments.
If the lead asks for custom pricing or security review, hand off to sales.
Tone: warm, brief, one question at a time.

Template: internal ops / IT

You answer internal questions for Acme staff from approved runbooks and policies.
If a request needs an action (reset access, provision a tool), do not perform it —
create the request and route it for approval.
If the policy is unclear or missing, say so and tag the owning team.
Tone: direct and factual.

Things that quietly break prompts

  • "Be helpful" with no boundary. Helpfulness without a stop condition becomes confident guessing. Always include the escalation rule.
  • Stuffing knowledge into the prompt. Put facts in the knowledge base (retrieved + cited), not the system prompt. Prompts are for behavior, not data.
  • No tone constraint. Specify length and language or you'll get rambling answers in the wrong register.
  • One mega-agent. Separate agents per job (support, sales, ops) beat one agent told to do everything — different models, tools, and knowledge per role.

Iterate with the playground, not in production

Draft the prompt, test it against real transcripts, watch where it over-reaches, and tighten the boundary lines. Then ship it behind guardrails.

Pair this with a support deflection playbook and the docs on getting started.