研究：花哨的harness让编码智能体更贵而非更好
原标题：Fancy harnesses make coding agents more expensive but not better, study finds
AI 摘要
山东大学两位研究者刘和韩在固定模型的前提下，用Claude Code、OpenCode和mini-SWE-agent三种harness测试了五个模型，发现更换harness带来的成绩差异与同一配置重跑两次的波动相当，但成本最高可增至三倍。论文题为《What does a harness buy? Mostly tokens.》，指出此前宣称的20分以上harness差距多来自单次运行的噪声，智谱宣称的2.4分领先也落在噪声范围内。唯一可测量的harness效应是OpenCode稳定落后最多9分，约一半差距源于输出上限处理方式不同。
正文节选
Fancy harnesses make coding agents more expensive but not better, study finds Makers tout score gains from new agent harnesses like Claude Code or OpenCode. A study finds that claim doesn't hold up. Swapping harnesses barely moves results more than running the same setup twice, but costs can triple. A coding agent pairs a language model with a harness, the system prompt, tools, and context management that make the model work inside a code repository. New harnesses ship every day, and leaderboard