Remember the era of fancy prompt engineering? Do elaborate coding agent harnesses actually make agents better?
We benchmarked popular coding setups on 100 real-world software engineering tasks using sudo L7.
The results:
➡️ Best harness additions: +2–3 points
➡️ More thinking: +11.3 points!
➡️ One coding agent setup: 8× the cost, no improvement
In one case, a harness spawned 17 agents to review a simple email change, and all 17 still missed a critical issue.
Sometimes smarter thinking beats more agents.