I assume your working directory is
~/.ssh/ when you run
I suspect there is a subdirectory named
~/.ssh/dev/). Check for it with
ls -lFd dev.
ls normally lists the contents of a directory. Adding the
-d option lists a directory as a directory itself.
Further, I suspect that there is a file,
~/.ssh/dev/dev which is what
ls -lF is displaying the information about.
If my suspicion is correct,
xattr dev displays the extended attributes of the subdirectory named
dev (not the file
dev/dev). The directory attributes probably are not the cause of this problem.
If this is confusing,
ls -lFR might help you see what's happening (the
-R option recursively lists subdirectories).
Finally, if my suspicion is correct and you're really trying to add a private key identity file named
~/.ssh/dev/dev to the ssh authentication agent, try
ssh-add dev/dev (or perhaps better,
ssh-add ~/.ssh/dev/dev, which should work no matter the permissions of the enclosing directory.