alt Hacker NewsTheres a study from earlier this year which suggests the opposite: https://arxiv.org/abs/2602.11988
Most of the agents.md and what people use it for / write into is does, in fact, not make a difference.
Now, sure, this study is a bit old for LLM standards - as everything beyond the current month is - but
a) I haven't seen any tangible evidence to the contrary and
b) Since the basic inner workings of LLMs haven't changed I'd be sceptical of this not still applying.
I think one major side effect of LLMs moving so fast is that best practices and how to use this tool is very much not catching up as fast.
No one knows what is best and what actually makes a difference, doubly so because LLMs are / very / hard to quantify - even benchmarks themselves are very rough estimations.
People do, in fact, use stuff which makes no difference all the times.
That's not what the study says. from the abstract:
> We conclude that while context files are useful for specifying non-standard coding practices, any attempts to improve performance should be rigorously evaluated before deployment.
The purpose of AGENTS.md is not to improve "coding performance" as the study looked at, it's to give an agent practical instructions that are useful to your specific workflow. For example you want it to use a certain format or specific tools for your project. This is stuff that can't be learned during training and must be loaded into the agent's context at the project level.