If you come from a strictly typed language like C++, prototypes seem like a good idea. In Perl almost always they aren't. Which is why mentioning prototypes in Perl often elicits a "Don't do that!" response.

What is your good reason for using prototypes? (There are some.)

Your sample non-prototype code looks pretty good to me because you have effectively named the parameters where they are being passed. That is hugely better documentation for someone reading the code later than simply passing a list and hoping for the best. Perl prototypes don't give type safety - they tend to enforce type matching which puts them on a level with C style casts. See Prototypes for the full glory of function prototyping.