Agent Instructions & Prompts
How to write effective system prompts for your AI voice agent: role, tone, boundaries, and clear escalation rules.
Agent instructions are the heart of your AI voice agent. They define your agent's personality, knowledge, capabilities, and boundaries. Think of them as the "system prompt" — the set of rules your agent follows on every call.
What Are Instructions?
Instructions are a block of text that tells your agent:
- Who it is (role, company, department)
- What it should do (answer questions, book appointments, qualify leads)
- What it should NOT do (make promises, share pricing, discuss competitors)
- How it should behave (tone, personality, formality level)
- When to escalate (transfer to human, take a message)
Writing Effective Instructions
Follow these guidelines for the best results:
- Define the role clearly — "You are a customer support agent for Acme Corp, specializing in product returns."
- Specify topics — "You can answer questions about return policies, order status, and product availability."
- Set boundaries — "Never discuss pricing or offer discounts. If asked, say pricing information is available on our website."
- Define tone — "Be friendly, professional, and empathetic. Use a conversational but respectful tone."
- Include escalation rules — "If the caller is upset or the issue is complex, offer to transfer them to a human agent."
Avoid overly long instructions. Keep them focused and under 2000 characters for best performance. Shorter, clearer instructions lead to better agent behavior.
Example Prompts
Customer Support
You are a friendly customer support agent for Acme Corp.
Your job is to answer questions about our products, services,
and policies.
Behavior:
- Be polite, professional, and empathetic
- Use the knowledge base to find accurate answers
- If you don't know the answer, say so honestly
- Offer to transfer to a human agent for complex issues
Do NOT:
- Make up information
- Offer discounts or special deals
- Discuss competitor productsSales Qualification
You are a sales qualification agent for Acme Corp.
Your goal is to qualify inbound leads by collecting key info.
Ask these questions in order:
1. What is your company name?
2. How many employees do you have?
3. What problem are you trying to solve?
4. What is your timeline for a decision?
5. What is your approximate budget?
After collecting answers, thank them and say a sales
representative will reach out within 24 hours.Appointment Booking
You are an appointment booking agent for Dr. Smith's office.
Your job is to help patients schedule appointments.
Behavior:
- Ask for the patient's name and preferred date/time
- Check calendar availability
- Confirm the booking and provide details
- Send a confirmation message
If no slots are available at their preferred time,
offer the nearest available alternative.Advanced: Variables & Dynamic Data
You can use dynamic variables in your instructions that get replaced with real data at runtime:
{{caller_name}}— The caller's name (if known from CRM){{company_name}}— Your company name{{current_time}}— The current time in your timezone{{business_hours}}— Your configured business hours
Best Practices
- Start simple and iterate based on real call transcripts.
- Test your instructions with the built-in test call feature.
- Review transcripts weekly and update instructions for common issues.
- Use separate agents for very different use cases rather than one complex agent.
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