They just addressed this with "Output styles"

https://code.claude.com/docs/en/output-styles

My experiments with output styles have not been sufficient to keep the model in check. It still spits out incomprehensible gibberish and load-bearing-isms.

Does anyone have an output style nailed down that actually works? If so, please share!

This solution:

1. Adds a small prompt to each turn with the agent[1]. 2. Is like a band-aid on a bullet wound, properly solving it would mean retraining the model and they probably are already working on it.

[1] https://x.com/_can1357/status/2090360068529111530