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 Changelog (best named 'Changes') to the distribution. It should list at least major changes implemented in newer versions.
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.
Fix the version(s).
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.