100% agree, Julian. The model provides the reasoning, but the loop/harness defines whether it actually succeeds or breaks in production.

I recently wrote about this while analyzing leaked system prompts. Specifically looking at how production agents treat tool use as a hard operating contract (orchestration logic, failure handling, parallel execution) rather than simple prompt decoration:

Are these really accidental leaks?

Without that explicit loop logic around the model, even the best model degrades quickly once edge cases hit.