Stop the spiral: Debugging Decay in AI coding tools

Find out why “just one more try” might be sinking your productivity

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This week, we’re diving into a phenomenon you’ve probably felt but maybe couldn’t name: why AI code assistants like GPT-4, Claude or Gemini start strong when debugging and then suddenly spiral into nonsense.

New research here quantifies what’s going wrong and which allows us to come up with a fix.

What’s Debugging Decay?

Debugging Decay Index (DDI) a framework to measure and predict when LLMs lose effectiveness in iterative bug fixing.

DDI gives us four actionable metrics:

  • Initial Effectiveness (E0​): how strong the model is on its first attempt

  • Decay Rate (λ): how fast performance drops

  • Strategic Cutoff (t0​): the best moment to reset context

  • Fit Quality (R2 ): how well decay matches observed behaviour

Bug ix success rate

bug fix success rate from the report

  • LLMs lose 60–80% of their debugging ability within 2-3 attempts in the same thread. By attempt 4–5, debugging is often worse than random guessing.

  • Claude Sonnet was the only model that didn’ show any significant sign of degradation making it “The model“ for coding.

So why does it happen?

  • Context pollution: Each failed fix pollutes the session with false paths.

  • Tunnel vision: The model clings to early wrong assumptions and can’t reset

  • Token bloat: More isn’t better. Excess tokens = lower accuracy.

  • Surface level reasoning: LLMs pattern match, they don’t truly understand.

  • Malicious compliance: Some fixes just silence the error, not solve it.

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How to beat this decay

1. Reset after 3 attempts:
- Start a new chat after 3 failed attempts. Fresh context = fresh thinking

2. Use strategic restarts: On reset, tell the model
- Who you are and what you’re building
- Purpose of the feature
- Current state and error trace
- Your debugging hypotheses

If you’re using Claude Code/Cursor leverage their instructions file.

3. Rotate models for second opinions
- Some models decay slower.

4. Rephrase for exploration:
- Don’t paste the same error again. Add hypotheses, contrasting examples or new test inputs to widen the model’s thinking.

5. Force hypotheses: Before asking for a fix, ask
- What are the top 5 likely causes?
- How would you test/falsify each one?
- Why might this fix fail?

6. Chunk it up
- Break the problem into atomic steps.

7. Track failed attempts:
- Prompt the model to keep a log:

8. Checkpoint your code
- Save working states regularly. Don’t rely on the model to remember what worked.

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🤓 Case Studies

  • The 2025 Stack Overflow Developer Survey reveals 84% of developers now use AI tools, but trust is dropping, with only 33% believing AI answers are usually accurate. Security, price and better alternatives drive tech rejection. Claude Sonnet is the most admired LLM .

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    Most developers haven't adopted AI agents yet. That’s why you’re here, right? 😉 Stay tuned, experiment early and watch everyone else play catch-up!

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Thanks for reading
- Sanket