package My::Test;

use strict;
use warnings;

use Carp;

sub import
{
	my $class = shift;
    croak "Number of import parameters is wrong, stopped " unless @_ == 3;
    # ...
}

1;

##</code><code>##

use My::Test "Param1", "Param2"; # dies because it are 2 params and not 3 as expected