Something like this? Warning: the resulting list of descending permutations will list every descending permutation, and it only stops when it returns to the original ascending list.

#!/usr/bin/perl -l

use strict;
use warnings;
use Algorithm::Loops qw(NextPermute);

my(@list) = (1..14);
do {
    print join(",", reverse @list);
} while( NextPermute(@list) );
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