Human in the loop

Why human-in-the-loop matters

Human-in-the-loop is a control on software that can take actions, not only write answers. Agentic AI is software that can take a sequence of steps toward a goal, such as checking an ads account and then changing a budget. Without a person in that sequence, the software will eventually do something you did not mean. Paid advertising accounts are a bad place to find that out, because a bad action spends real money.

The control looks like this. The AI co-worker (an AI teammate that can do marketing work with you) prepares the work. A person approves it, or the job is limited to alerts that a person still has to act on. Strategy, taste, and client relationships stay with people. The co-worker is extra help, not a replacement for the team.

Let's take a plumbing company as an example. They buy Google ads and Facebook ads to get homeowners who need a plumber this week. A light loop looks like this: the AI watches cost per lead (how much they spend each time someone fills the "book a visit" form) and sends a Slack message when that cost jumps from $20 to $50. A person at the plumbing company still decides what to do. Nothing in the ads account changed by itself.

Let's take a plumbing company as an example. They buy Google ads and Facebook ads to get homeowners who need a plumber this week. A heavier loop looks like this: the AI proposes moving $2,000 of the monthly ad budget from Facebook to Google, because Google is bringing cheaper booked visits. The $2,000 does not move until someone at the plumbing company clicks yes. A script that moves the $2,000 at 2am with no log and no person asked is not a co-worker. It is unsupervised spend.

How to read human-in-the-loop

Human-in-the-loop is not on or off. It is a scale of how much a person has to do before the AI is allowed to change anything in a live ads account.

• A Slack message when a plumbing company's cost per lead (ad spend divided by form fills) spikes is a light loop. The AI noticed something, and a person still has to act.
• A $2,000 budget move that sits until someone at the plumbing company clicks yes is a heavy loop. The AI prepared the change, and the spend does not move without a person.
• A dashboard the plumbing company still has to remember to open is not a loop. Nobody is watching, and nobody is asked to approve.

Write down which jobs the AI may run on its own and which jobs must wait for a person. If every job waits, you bought a report that still needs a human operator. If no job waits, you will find out about a bad action in the ads manager after the money is gone.

Chat tools connected over MCP (Model Context Protocol: a way for ChatGPT, Claude, Cursor, or n8n to read your marketing data) stay read-only on purpose. Changing budgets and pausing ads belongs in the product where approvals already live, not in an outside chat window.

Common human-in-the-loop mistakes

One common mistake is adding an approve button and never looking at it. A $2,000 budget proposal for a plumbing company's ads that sits in a queue for a week is not human-in-the-loop. Nobody was in the loop.

Another common mistake is refusing any write access, then wondering why the AI co-worker is just another report. If the software cannot pause a dead ad even after you say yes, you still do all the clicking.

Decide the split before you turn anything on. Reports and Slack flags can run without approval. Pausing a dead ad can wait for a yes, or run inside a cap you already set, such as "never pause more than two ads a day." Account-level budget allocation (moving a large share of the month's spend from one channel to another) should wait for a person.

If you cannot name which jobs run on their own and which jobs wait for a person, you do not have a loop. You have hope that the software will behave.