This. Projects need to stop inventing their own root level files and directories.
Stop polluting the root dir.
I'm not a fan of the name "well-known", but at least it's a convention [1].
I think it'd be great if we took something like XDG [2] and made it common for repositories, build scripts, package managers, tooling configs, etc.
I believe with direnv or a similar tool (e.g. Emacs’s directory-local feature) one can append $REPO/.config to XDG_CONFIG_HOME, $REPO/.local/bin to PATH and so on so that when in the context of a particular directory everything Just Works.
I think all this agentic stuff could live quite happily in $REPO/.config/agents/.
I've been in IT for a long time and configured Apache, Nginx, even IIS a bit back in the day, but I actually didn't know about well-known.
I guess I was one of the lucky 10000 :-)
.config is a good name, and has a small following
https://dot-config.github.io