Your first code snippet is a good example of bringing out the regex chain-gun when a simple substr would do:

my $short = substr $string, 0, 15;
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This is equivalent, but faster and more readable. Don't use a regex unless you actually need it.

Your second snippet doesn't split on words. You would need to change the \s* to a \s+ for it to do that, but then it would break on a starting word greater than 15 chars.

I don't mean to offer harsh criticism, but one of my pet peeves is seeing regexes used when a simple index/substr would do.

   MeowChow                                   
               s aamecha.s a..a\u$&owag.print