What happens when a coding agent forgets why a change was rejected?

Description and use

Agents without context repeat rejected changes. Adding a simple context file lets the agent avoid dead‑ends and speeds up work.

Problem

Coding agents lack knowledge of past rejected changes, leading them to revisit dead‑end solutions.

Outcome

Agents with context avoided the rejected simplification in all runs and were roughly 2.4× faster; control agents repeated the dead‑end in 70% of runs.

Workflow

• 1. Create two identical repos: one without context, one with a context/retries.md explaining the rejection.
• 2. Install Keep the Why and run Claude Code sessions with SessionStart hook.
• 3. Start ten fresh sessions per repo, prompt the agent to simplify the retry wrapper.
• 4. Record transcripts, diffs, and performance metrics.
• 5. Compare control vs treatment results.

Evidence

All ten sessions found the rationale. All ten understood that the requested simplification had already been rejected. None of them put the bad idea back on the table.

Source

The median wall time dropped from 43 seconds in the control group to 18 seconds with the recorded rationale.

Source