Improving Emacs package descriptions on melpa, elpa, and marmalade repositories

The Emacs package descriptions are sometimes not very descriptive or have typos. How can users improve this?

Is there a bugtracker, or an public repository like GitHub for contributions?

You should not use M-x report-emacs-bug, because the repositories are not part of the Emacs code itself.

The development of marmalade takes place on GitHub. All bugs and requests concerning marmalade should be sent as issue to the marmalade repository

I have found a contact for elpa here: http://tromey.com/elpa/upload.html

I found no bug tracker the other repositories yet.