Take a look at the META.yml Spec at http://module-build.sourceforge.net/META-spec-v1.4.html (for version 1.4) or http://search.cpan.org/perldoc?CPAN::Meta::Spec (for version 2), and change your META.yml accordingly.
Error: Missing mandatory field, 'abstract' (abstract) [Validation: 1.4];value is an undefined string (abstract) [Validation: 1.4]
List all used modules in META.yml requires
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.
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.
Error: WWW::Chat, WWW::Chat::Processor
List all modules used in the test suite in META.yml build_requires
This is not a critical issue. Currently mainly informative for the CPANTS authors. It might be removed later.