Provide a short description in the NAME section of the pod (after the module name followed by a hyphen) at least for the main module of this distribution.
Add a section called "LICENSE" to the documentation, or add a file named LICENSE to the distribution.
Add =head1 LICENSE and the text of the license to the main module in your code.
Add a META.yml to the distribution. Your buildtool should be able to autogenerate it.
Remove the POD errors. You can check for POD errors automatically by including Test::Pod to your test suite.
Error: Speech-Rsynth-0.03/Rsynth.pm -- Around line 489: You can't have =items (as at line 496) unless the first thing after the =over is an =item
Add =head1 LICENSE and/or the proper text of the well-known license to the main module in your code.
Add a META.json to the distribution. Your buildtool should be able to autogenerate it.
Define the license if you are using in Build.PL. If you are using MakeMaker (Makefile.PL) you should upgrade to ExtUtils::MakeMaker version 6.31.
This is not a critical issue. Currently mainly informative for the CPANTS authors. It might be removed later.