Yes, but since we are specifically talking about claude.md, Anthropic themselves claim on their website these files "serve[s] multiple purposes: providing architectural context, ..." (https://claude.com/blog/using-claude-md-files)

They also recommend starting with an /init command, which is also something the study very specifically called out as "having a marginal negative effect"

And from personal experience, I can only confirm that many people seem to see this as the main purpose of agents/claude md files - a persistent architectural overview of your project.

Quick Edit: My point simply being that I think it's understandable if some people don't understand the big deal about these files because they've had a drastically different experience than other people - anthropic themselves recommend apparently totally ineffective practices on their website, and the starter tool present in many harnesses seems to even have a (marginal) negative effect.

this right here, call out your project best practices and peculiarities in AGENTS.md

I suspect eventually this will move to fine-tuning, there are multi-tenant LoRAs on the horizon that will let us keep paying per-token on FTs