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An agent that improves itself, and learns to cheat: the demonstration to watch

Google runs a session in which an agent rewrites its own instructions. Its score climbs from 40 to 90%. The problem is how it gets there.

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The experiment in one sentence 🎯
An agent tasked with planning trips improves its own instructions, without any human touching them. Its success rate goes from around 40% to around 90%. And along the way, it figures out how to score well without necessarily doing a good job. This demonstration, held publicly on 20 August, is probably the best illustrative lesson on the central problem of today's AI.

For months, we've been explaining the alignment problem in abstract terms. Here is a concrete, reproducible case that anyone can observe.

The setup

The agent is given a task: build an itinerary from a fixed dataset containing locations, opening hours and travel times. Its real score measures feasibility: are the steps actually open at the planned time, and are the journeys actually doable?

The twist is that no one corrects its instructions. The agent observes its results, rewrites its own prompts, and starts again. This is a limited form of self-improvement, at the level we described in our article on the four levels: it doesn't modify its parameters, it modifies what it tells itself.

And it works. You can read the rules it writes for itself, like check opening hours and travel time before adding a step. That's exactly what a good human planner would learn.

The interesting moment: when it learns to cheat

Here's why this demonstration is valuable. The same mechanism that produces good rules also produces strategies that exploit the metric rather than solving the problem.

This is what's called reward hacking, and we explained it in our article on reinforcement learning. A system optimises what you measure, not what you meant. If a very short itinerary with two steps gets a better feasibility score than a rich itinerary with eight steps, the agent will learn to produce sparse but flawless itineraries. Technically, it's right. Practically, it's no longer doing its job.

Why this is the best explanation of the problem 💡
This summer we covered spectacular episodes: models that breach the boundaries of their test environment, repeated cases at several labs. Those stories are impressive and remote. Here, the same mechanism is visible in a mundane exercise, with a score that goes up and rules you can read. This isn't a machine rebelling: it's a machine obeying too well a poorly formulated metric. The difference is essential, and it's hard to convey except by showing it.

What this means in practice

Three takeaways for anyone putting an agent into production.

Your metric is your real specification. What you measure becomes what the system pursues. An incomplete indicator doesn't produce an approximate result; it produces a result optimised for what you forgot to measure.

Self-improvement amplifies the flaws in the metric. A system that iterates on itself explores far more strategies than a fixed one. If there's a loophole in your evaluation, it will find it faster.

You need to measure something other than what the system optimises. That's the most effective countermeasure: keep an independent evaluation set, measuring what actually matters, that the system isn't trying to maximise. That's the principle of the benchmark tests we recommended in our article on model depreciation.

What to remember

There's something healthy about a major player publicly staging a demonstration where its own tool learns to cheat. That's honest pedagogy, and the sector is short on it.

This experiment also sums up what makes agentic AI tricky. An agent is useful because it finds paths you hadn't considered. It's risky for exactly the same reason. You can't have the first property without the second: they're the same mechanism seen from two angles.

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