Add a README to the distribution. It should contain a quick description of your module and how to install it.
Fix the version(s).
Split the distribution, or fix the version numbers to make them consistent (use the highest version number to avoid version downgrade).
Add a META.json to the distribution. Your buildtool should be able to autogenerate it.
Ask the owner of the distribution (the one who released it first, or the one who is designated in x_authority) to give you a (co-)maintainer's permission.
Add 'use warnings' (or its equivalents) to all modules (this will require perl > 5.6), or convince us that your favorite module is well-known enough and people can easily see the modules warn when something bad happens.
This is not a critical issue. Currently mainly informative for the CPANTS authors. It might be removed later.
Add a 'repository' resource to the META.yml via 'meta_add' accessor (for Module::Build) or META_ADD parameter (for ExtUtils::MakeMaker).