I remember trying to parse some not-well-documented xml.zip format myself, writing similar code using XML::Simple. Unfortunately, I didn't have a chance to rewrite it using XML::Twig. Fortunately, now it's not used anywhere.

What about writing something like this?

use XML::Twig;
my @fails;
my $parser = XML::Twig::->new(twig_roots => {
 '/items/client/site/servers/server/failed_checks/check/description' =
+> sub { push @fails, $_->text },
 '/items/client/site/servers/server/overdue/description' => sub { push
+ @fails, $_->text },
})->parse_file($fail);
my $report = @fails ? 1 : 0;
[download]

The code is fully untested, but I could try fixing it if you provide a bit of example input data.

Another option could be using Data::Diver.