Yeah, layers of abstraction tend to obscure error messages, making precise documentation necessary. How about this?

package MyObject;
use Moose;
use MooseX::WithCache;
with 'MooseX::WithCache' => { backend => 'Cache::FileCache' };
has uuid => ( is => 'rw', default => 0 );
has arg1 => ( is => 'rw' );
has arg2 => ( is => 'rw' );
no Moose;

sub get_object {
    my $self = shift;
    my %args = @_;
    my $obj;
    if ($args{uuid}) {
        $obj = $self->cache_get( $args{uuid} );
    }
    unless (ref $obj) {
        my $uuid = 42; # use real UUID generator!
        $obj = MyObject->new( %args, uuid => $uuid );
        $self->cache_set( $uuid => $obj );
    }
    return $obj;
}

package main;
use Data::Dumper;
use Cache::FileCache;
my $object = MyObject->new( cache => Cache::FileCache->new );

my $foo = $object->get_object( arg1 => 'foo', arg2 => 'bar' );
print Dumper $foo;

my $bar = $object->get_object( uuid => 42 );
print Dumper $bar;
[download]

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)