Your agent's instructions are the single most important factor in how well it performs. This guide will help you write clear, effective instructions that get the results you're looking for.

Instructions are written in plain English. There's no special syntax, no code, and no technical jargon required. You're simply explaining to the agent what you want it to do, as though you were briefing a new member of staff.

Start with a clear description of what the agent should do and be specific about the goal and the steps involved.

Vague: "Handle new enquiries."

Specific: "When you receive a new enquiry, check whether the property they're asking about is still available. If it is, send them an email confirming availability and suggesting three viewing slots over the next week. If the property is no longer available, send them an email letting them know, and suggest two similar properties in the same area."

Tell the agent how it should communicate. Should it be formal or friendly? Should it use the agency's name? Should it avoid certain language?

"Use a warm, professional tone. Always sign off with the branch name and phone number. Avoid using exclamation marks."

Be explicit about what the agent should and shouldn't do. If there are edge cases or exceptions, spell them out.

"Never offer a discount without approval. If the applicant mentions a complaint, do not respond - instead, flag the enquiry for a manager to review."

If the agent is producing content (emails, blog posts, notes), describe what good output looks like. You can include examples if it helps.

"Emails should be no longer than 150 words. Always include a clear call to action. Here's an example of the kind of email I'd like you to write: ..."

Be specific over being brief. Longer, more detailed instructions almost always produce better results than short, vague ones. Don't worry about writing too much - clarity is more valuable than brevity.

Think about edge cases. What should the agent do if the data it receives is incomplete? What if there's no email address? What if the property is under offer? Addressing these scenarios in your instructions prevents unexpected behaviour.

Iterate. Building a great agent is an iterative process. Start with a set of instructions, test the agent, review the output, and refine. Cortex's test mode is designed specifically for this workflow - see Testing and improving your agent help article for more.

Use the AI builder. If you're struggling to articulate what you want, try the "Build with AI" option. The AI assistant will ask questions and help you shape your instructions.