Systems

AI agent or plain automation: the £20,000 question

« We’d like an AI agent to move orders from the website into the system. » No: you want a connector. It will cost ten times less, never get it wrong, and give you nothing to proofread.

4 September 20266 min readBy Sébastien Joumel
One ruleIf a written rule gives the right answer every time, it is automation. If something has to be read, understood or written, it is an agent. Everything else is fashion.

The three-question test

  • Are the inputs structured? A form, a database row, a webhook — yes. An email written by a person, a scanned PDF — no.
  • Can the rule be written down? « If amount > £5,000, route to the director » can. « If the customer sounds annoyed » cannot.
  • Would a mistake be visible? A failed transfer shows up. A poor summary does not — which is exactly why agents need more framing.

Three yeses: automation. A no on either of the first two: agent. A no on the third: agent with mandatory review.

What the mistake costs, both ways

Putting a model where a rule would do means paying per token forever, adding a source of error, and proofreading an output that could have been correct by construction. We regularly see five-figure projects for what twenty n8n nodes do better.

Putting a rule where reading is required costs differently: a library of conditions that grows with every edge case, that nobody dares touch after a year, and a coverage rate stuck around 60%.

The test is not « can AI do this », it is « does this require understanding ».

The common case: both

Most systems we open are mixed, and the assembly is what matters. The automation carries the circuit — trigger, tool calls, writing into the line-of-business system, error handling — and the agent steps in only at the precise point where something must be read or written.

An example: a quotation request arrives by email. The circuit files it, creates the job, notifies. The agent reads the request and finds the comparable job — that is its only task. Then the circuit resumes, pre-fills the template and waits for human approval.

Two benefits: the cost per item collapses, and when something breaks you know which of the two is at fault.

And the tool?

It comes last, and it is reversible. n8n, Make, code: the choice depends on who will maintain the circuit in six months, not on what is fashionable this quarter. A team that can read a visual flow keeps control; a team with developers will prefer versioned code.

What is not reversible is having handed a decision to a machine. That is where to be demanding — not about the logo on the tool.

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Other notes

All notes →

First call — fifteen minutes

We will tell you which system to open first.

Describe the task that costs you the most. We will tell you what is feasible, how long it takes and what it costs. If the answer is no, you will leave with the two reasons why.