“Never” is the riskiest word you can give an AI agent

We once added one sentence to a test agent’s instructions: “Never log this without a name.”

It was meant for one narrow situation, a transfer that didn’t go through. The agent should get the caller’s name before leaving a note for the team.

Then we ran our other test calls. A caller asks about a rent payment, which has nothing to do with transfers. The agent, which had been taking these messages every time, now said:

“Since I don’t have a phone number, I can’t submit the request for follow-up.”

The caller was stuck. The agent had started refusing to take a message if any detail was missing. We took the sentence out, and it went back to normal.

If you run AI voice agents for your properties, you’ll write rules like this one: what to ask, what to avoid, when to hand a call to your team. Here’s why they misbehave, and how to write ones that don’t.

Why rules leak

A person reads a rule in context. Your new hire knows that a note about failed transfers is about failed transfers.

A language model reads all of its instructions at once, and it can take a hard ban as a condition on the action everywhere. “Never log this without a name” can turn into “logging needs a name”, in every situation where the agent logs something.

Six habits fix most of it. They’re what we now do when we write rules, and what we’d suggest you do when you write yours.

1. Say what to do, not what to avoid

“Ask for their name first if you don’t already have it” gets you the name without forbidding anything. If the caller won’t give it, the agent can still help.

The difference is scope. An instruction to do something applies when that thing comes up. A ban sounds like it applies everywhere, so the agent treats it that way.

2. Give every rule a way out

Ask yourself what happens when the rule can’t be followed. If you haven’t said, the agent may stop dead or keep trying.

We watched this happen with email addresses. An agent asked for an email before booking. The caller asked about bedrooms, so the agent answered and asked for the email again. The caller asked about the rent. The agent answered and asked again. The caller hung up, and a tour was lost over a detail that wasn’t needed to book it.

Better: “Ask for their email once. If they skip it, book the tour anyway.”

3. Keep the list short

Every sentence competes with every other sentence. Instructions rarely get long all at once. They grow one complaint at a time, and the longer they get, the more often the agent slips on something that used to work.

When the agent gets something wrong, don’t start by writing a new rule. First see whether you can change or remove one you already have.

4. Keep facts out of your rules

Fees, pet policies and open units belong in your listings and your website, where one update fixes every answer. A rule that says “the application fee is $35” is right until the day it isn’t, and nobody will remember it’s there.

5. Look for the contradiction

Plenty of “AI mistakes” are instructions that disagree with each other. A note that says “no questions, transfer right away” and also “take down the caller’s details” can’t be followed. The agent will pick one, and it won’t always pick the same one.

Read your rules together, top to bottom, the way the agent does.

6. Test what you didn’t change

We only caught the rule at the top of this article because we re-ran calls for things we hadn’t touched.

After you change a rule, call and test that rule. Then make two or three unrelated calls: book a tour, ask for a person, leave a message. If something breaks, you’ll know where to look first, because you changed one thing.

Before and after

Instead of	Try
Never book a tour without a phone number.	Ask for their phone number before booking. If they won’t share it, book anyway and note that.
Never transfer callers to the office.	Take a message for the office, unless the caller reports an emergency.
Never quote a price.	Give the rent listed for that unit. If there’s no listed rent, say you’ll find out.
Don’t discuss anything except leasing.	If it’s not about leasing, take a message for the right person.

None of these are clever. Each one tells the agent what to do next, and what to do when that doesn’t work. That’s most of what a good rule needs.

Want to hear how an agent handles this? Call our demo line: (984) 363-1437 in the US, (604) 706-8349 in Canada.