# Foo.pm
package Foo;
use strict;
use Attribute::Handlers;
use Exporter 'import';

our @EXPORT = qw/Sorted/;

sub Sorted :ATTR {
  print "all sorted"
}

1;

# attr.pl
#!/usr/bin/perl 
use strict;
use warnings;

use Foo;

my Foo $tst1 :Sorted;
my $tst2 :Sorted;
print "done\n";

##</code><code>##

Invalid SCALAR attribute: Sorted at /home/arun/attr.pl line 8.