More red-flags:

• Example code is not perlstyle-ish, eg. innappropriate CamelCaps.
• Capitalized "PERL"
• Modules with a compatability-with-my-company mode

Green-flags

• A License section, in addition to the other standard sections mentioned elsewhere.
• /"W3C"/i
• Has a Tutorial, Overview, Introduction or Cookbook.

I like and use the "references and distinguishes other modules" green flags mentioned by others.

Brad