Originally published on AI Tech Connect.
What you need to know Generating a fix and establishing a cause are different skills, and agents have one of them. A plausible patch at the point of failure is what a language model is good at. Locating where the behaviour changed is not. Three documented agent failure modes are debugging failures. Ineffective backtracking, poor resource awareness and instruction drift, all named in the 2026 case-study paper on open-ended AI research (arXiv 2607.27191). Every stage ends with a gate, not a judgement. A deterministic failing test. A named commit or version boundary. A stated causal chain. A revert check that goes red. Bisection is the highest-value agent task in the loop. Mechanical, verifiable, and structurally immune to a favoured hypothesis: the next commit to test is chosen by the last…
