It's not clear to me what you are trying to achieve, but maybe the following will point you in the right direction:

use strict;
use warnings;

while (<DATA>) {
    next if ! (/Line above/ .. /Line below/);
    next if ! /Description\s+"([^"]*)"/;
    print "Found $1 in line $.\n";
}

__DATA__
Line above
Description "xyz"
Line below
 
Line above
Line below
[download]

Prints:

Found xyz in line 2
[download]