$ perl -E 'defined(%h)' 2>&1 | splain
defined(%hash) is deprecated at -e line 1 (#1)
    (D deprecated) defined() is not usually useful on hashes because it
    checks for an undefined scalar value.  If you want to see if the hash
    is empty, just use if (%hash) { # not empty } for example.

        (Maybe you should just omit the defined()?)