> You can also just ask the LLM: are you sure this is idiomatic?

I found the reverse flow to be better. Never argue. Start asking questions first. "What is the idiomatic way of doing x in y?" or "Describe idiomatic y when working on x" or similar.

Then gather some stuff out of the "pedantic" generations and add to your constraints, model.md, task.md or whatever your stuff uses.

You can also use this for a feedback loop. "Here's a task and some code, here are some idiomatic concepts in y, please provide feedback on adherence to these standards".