I suppose if all you're doing is just providing the glue between Perl and the library, you _could_ get away with that.
in reply to On providing documentation with your modules
However, if there are any cases where what the Perl code is doing differs from what the C++ code is doing, you should document the hell out of them.
It would also be good to provide several example programs, that people can study and use as their starting point. I generaly dislike cargo cult programming, but when you're familiarizing yourself with a new library, sometimes using a modern amount of CC is the only way to get your feet wet.
Compare what you are doing to PerlTk - although most of the calls look very much like the calls in TclTk, there are enough subtle differences that they felt the need to write a lot of very good documentation for each class.