sub worker {
    my ($self, $subclass, $name, $code) = (undef,'Worker','work');
    if( @_ == 2) {
        ($self,$code) = @_;
    } elsif( @_ == 3) {
        ($self,$name,$code) = @_;
    } elsif( @_ == 4 ) {
        ($self,$subclass,$name,$code) = @_;
    };
    my $n = "$self\::$subclass\::$name";
    no strict 'refs';
    *{$n} = $code;
};

__PACKAGE__->worker('Tool' => 'toolit' => sub {
    ...
});

__PACKAGE__->worker(sub {
    ...
});