On many filesystems, a lot of data about a file is not attached to the content of the file, but stored in a master filename and metadata table graph tree of some sort, and the address offset within that metadata used to retrieve the contents on disk can be a duplicate of another entry, without that situation instantly leading to a filesystem driver crash. Some filesystems officially support such duplicates as well as equivalents of HTTP 3xx, some you can just do as a matter of fact and fsck would have some words about it.

Default filesystems for all Unix, Linux, WinNT, all do.

Yes. The thing is that creating a link will not do it recursively for all subdirectories. Even worse, in the subdirectories I didn't want to place a claude.md in the first place but just have agents.md.

That was the idea.... For the toplevel it works because of the @AGENTS.md and this is also the part the link would solve.

Thanks for all the great advice and explanations.