Fancy harnesses make coding agents more expensive but not better, study finds

A controlled study found that switching coding-agent harnesses such as Claude Code, OpenCode, and mini-SWE-agent changes pass rates by little more than rerunning the same setup, while cost per task can triple, driven mainly by the system prompt resent with every step. The finding, reported by The Decoder, indicates harness choice has limited effect on agent accuracy but a large effect on expense.

A controlled study shows that switching between coding-agent harnesses like Claude Code, OpenCode, or mini-SWE-agent barely moves pass rates more than rerunning the same setup. Cost per task, however, can triple, driven mainly by the system prompt that gets resent with every step. The article Fancy harnesses make coding agents more expensive but not better, study finds https://the-decoder.com/fancy-harnesses-make-coding-agents-more-expensive-but-not-better-study-finds/ appeared first on The Decoder https://the-decoder.com .