I deleted 90% of my harness (And It Got Better)

Alt Title: Why Models Are Superhuman with Bash (Where Humans Fail)
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I spent my day to day building a agents with custom tools for everything.

Every few month I decide to delete everything and see what is not needed anymore. I stripped out every dedicated tool until only Bash remained. I cut the prompt to 300 tokens and made the execution loop asynchronous.

Benchmark scores jumped. Experience went up.

Rich Sutton called this the Bitter Lesson: building human heuristics into AI always loses to general methods backed by compute. Models are now superhuman with the bash. A frontier model can synthesize an ad-hoc 15-line pipeline combining Python AST parsing, ripgrep, git diffs, and subshells in 200ms to make progress on a users task, there is no need for dedicated edits, search or grep tools anymore.

Learn how to delete your code.