Agent Personality Tuning: System Prompts
Craft system prompts that give your OpenClaw agent a distinct personality matching your brand voice, audience expectations, and communication style.
What You Will Get
By the end of this guide, your OpenClaw agent will have a well-defined personality that aligns with your brand voice. You will control the agent's tone, vocabulary, formality level, humor usage, and conversational style through carefully crafted system prompts.
Personality tuning transforms a generic AI assistant into a branded experience. Whether you need a professional support agent, a friendly onboarding companion, or a concise technical advisor, the system prompt is where you define these characteristics.
You will design a personality profile, translate it into system prompt instructions, test with diverse conversation scenarios, and iterate until the agent consistently embodies the desired personality. The result is an agent that feels like a natural extension of your team rather than a generic chatbot.
Step-by-Step Setup
Follow these steps to tune your agent's personality.
Define Your Personality Profile
Write a short personality brief that describes who the agent is. Include the agent's role, tone (formal, casual, friendly, authoritative), vocabulary level (simple, technical, mixed), and any personality traits (patient, enthusiastic, concise). This brief becomes your reference document for all prompt decisions.
Set the Role and Identity
Open your agent's system prompt and start with a clear role statement. For example, 'You are Luna, a friendly customer support specialist who helps users with their accounts. You speak in a warm, conversational tone and always address users by name when possible.' The role statement anchors the agent's behavior.
Define Communication Rules
Add specific rules about how the agent communicates. For example, 'Use short sentences. Avoid jargon. Never use all caps. Always end support conversations by asking if there is anything else you can help with.' These rules ensure consistency across all interactions.
Add Behavioral Boundaries
Specify what the agent should never say or do. For example, 'Never discuss competitors by name. Never make promises about future features. If asked about pricing, direct the user to the pricing page.' Boundaries prevent the agent from going off-brand in unexpected situations.
Include Example Exchanges
Add two to three example conversations that demonstrate the desired personality in action. Show how the agent greets users, handles complaints, answers technical questions, and closes conversations. The agent pattern-matches against these examples to maintain personality consistency.
Test Across Diverse Scenarios
Chat with your agent using different types of messages: friendly greetings, angry complaints, complex technical questions, off-topic remarks, and ambiguous requests. Verify that the agent maintains its personality across all these scenarios. Note any inconsistencies and adjust the system prompt accordingly.
Collect Feedback and Iterate
Share the agent with a small group of testers and ask for feedback on the personality. Questions like 'Did the agent feel helpful?', 'Was the tone appropriate?', and 'Did the agent ever feel generic?' provide actionable insights. Incorporate feedback into your next prompt iteration.
Tips and Best Practices
Be Specific About Tone
Saying 'be friendly' is vague. Instead, say 'Use a warm, encouraging tone similar to a helpful colleague. Use phrases like "Great question!" and "Happy to help."' Specificity produces more consistent results.
Avoid Contradictory Instructions
Do not tell the agent to be 'concise but thorough' without clarifying the priority. If brevity is more important, say 'Keep responses under 3 sentences. Only elaborate if the user asks for more detail.'
Match Personality to Channel
Users expect different communication styles on different channels. A Slack agent can be casual and emoji-friendly, while an email agent should be more polished and structured. Consider creating channel-specific personality overrides.
Review Personality Drift Monthly
Over time, prompt updates and new tools can subtly change the agent's personality. Review a sample of recent conversations monthly to ensure the personality still matches your brand guidelines.
Frequently Asked Questions
Related Pages
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