Study finds developer-written guidance can cut coding agent costs

In an arXiv preprint, researchers found that developer-written guidance reduced coding agent costs by up to 41.73% in their tests. They examined repeated file retrieval, similar script generation and test reruns across coding tasks, then evaluated ways to curb those behaviors on held-out software repair benchmarks. The three behaviors appeared in 79.00%-98.00% of tasks and accounted for up to 22.75% of task cost. The savings depended on the remedy: a more structured retrieval method increased costs by up to 28.14% in some tests, while guidance generated by the agents was less effective than developer-written guidance.