no rules returns error

jv.pl

#!/usr/bin/env perl

use v5.16;
use warnings;
use lib 'local/lib/perl5';

use JSON::Validator;
use Data::Dumper;

my $v = JSON::Validator->new;

$v->schema({});

my @errors = $v->validate({a => 1});

print Dumper(\@errors);

__END__

prints this:

$VAR1 = [
          bless( {
                   'path' => '/',
                   'message' => 'No validation rules defined.'
                 }, 'JSON::Validator::Error' )
        ];

However this page: http://json-schema.org/ says that schema {} allows (should allow) anything.