AI agent development
AI agent development is not really a modelling problem. It is a series of decisions about how far the thing is allowed to act without a person, and each step of that ladder costs more to get wrong than the one before it. Most projects should stop two rungs lower than they plan to.
The four rungs, and what each one buys you
- 1 — It watches and tells you. No actions at all. It reads, notices, and raises the things that matter. Boring, cheap, and it already recovers most of the value on a job nobody has time to review daily.
- 2 — It drafts and you sign. It prepares the order, the reply, the report, and a person approves. This is where most business value actually sits, because the slow part was never the clicking.
- 3 — It acts inside a limit. Routine work under a spend cap, a margin floor, a volume ceiling. Anything outside stops and names the reason. This rung needs the audit trail to exist first.
- 4 — It acts and adjusts its own limits. Rarely worth it, and the point at which the guardrail becomes decoration. I have not needed rung four for anything, and I would argue hard before building it.
How you prove one before it touches money
The test is not a demo. It is a week of the agent running beside the person who does the job now.
- It proposes, the person decides, and both answers are written down. Agreement rate is the number that matters, not accuracy in the abstract.
- Every disagreement gets read by a human once. Half of them will be the agent being right about something nobody had noticed.
- Feed it a deliberately abnormal week — a promotion, an outage, a spike — and watch whether it stops. If it never stops, the guardrail is not wired to anything.
- Only then does it get a limit and permission to act.
What makes an agent expensive, and it is never the model
- Data that has to agree first. If two systems hold different numbers for the same record, the agent will pick one and act confidently. Joining them is usually the longer half of the project.
- The audit trail. Every decision with the inputs it used, kept long enough to settle an argument in three months. Skipped in demos, needed in production.
- The stop list. The explicit set of things it must never decide alone. Writing it takes real meetings with the people who own the risk, and it is the actual deliverable.
- The monthly bill. Model calls, storage, the machine it runs on. A number that grows with your volume and belongs on the table before the build, not after.
Build an AI agent, or buy an agent platform
- The platform sells the plumbing. An AI agent platform gives you the orchestration, the retries, the tool wiring and a screen to watch it on. That is real work you no longer have to write. It is also the cheap half.
- The expensive half stays yours. Data that agrees with itself, the audit trail, the stop list. No platform writes those for you, because they are decisions about your business wearing the clothes of software.
- Buy when the job is standard. Common systems, an ordinary shape of work, no unusual boundary — the platform gets you there faster and cheaper than I can, and I will tell you so in the first hour.
- Build when the boundary is specific. A custom AI agent earns its cost when what it must never do is particular to you, or the systems it has to reach are your own. That is exactly where a platform starts charging you to work around itself.
- Price both at your real volume. Platforms charge per seat, per run or per action. The number that looks obvious at ten users is a different decision at three hundred, and that arithmetic belongs before the pilot rather than after it.
Too early for you if
- The job happens a few times a month. An agent earns its keep on repetition.
- Two people in your team would judge the same case differently. Agree the rule first — that alone is worth the meeting.
- Nobody owns the exceptions queue. An agent that stops and names a reason still needs someone reading it the same day.
Agents already acting, and their limits
- Returns & defects handler — rung two in production: every claim judged against your rules the moment it lands, and one batch handed over to sign off each morning — the decision is made by the person, not by the machine.
- Customer-chat assistant — two models working together — one drafts the reply, a second independent one blocks anything it should not say.
- Recommendation shelves — the guardrail that fired for real: it held a shelf when healthy stock fell 30% in a week, and named the reason instead of buying into the fall.
- New-arrivals radar — rung one, doing its job quietly: the category scanned on a schedule and the movers ranked.
Honest answers
What does AI agent development involve?
Deciding how far the thing may act without a person, and building the evidence for that decision: the joined data it reads, the limits it acts inside, the explicit list of things it must never decide alone, and a record of everything it did.
How autonomous should an agent be?
Usually one rung lower than planned. Watching and telling you, or drafting for a person to sign, recovers most of the value at a fraction of the risk. Acting inside a limit is worth it once the audit trail exists.
How do I know the agent is any good before it acts?
Run it beside the person doing the job for a week. It proposes, they decide, both answers get written down. The agreement rate is the number that matters — and reading the disagreements is where you learn the most.
What makes agent projects expensive?
Data that disagrees with itself, the audit trail, and the stop list. The model is a line item. If an estimate does not name who owns the data work, it is not an estimate yet.
Can an agent spend money on its own?
Inside limits you set — routine, in-threshold work only. Anything past the limit stops and routes to a person with the reason attached. Nothing that costs money gets decided without a signature.
Should we build one or buy an agent platform?
Buy, if your systems are common and the job has no unusual boundary — a platform will be faster and cheaper than a build, and I will say so in the first hour. Build when what it must never do is particular to you. Either way the data, the audit trail and the stop list are yours to sort out, and they are the expensive part.
Is an AI agent for business different from the ones in the demos?
The demos show several models planning together. An AI agent for business is almost always one narrow job, one set of systems, and a written list of things it may never do — which is boring to watch and the reason it survives a Tuesday.
Tell me what you would let it decide
Describe the job and where you would draw the line on what it may do alone. I will tell you which rung is right, what has to be true before it gets there, and what would make it expensive. The first conversation is an hour and it is free.
Book that hour →