From Online Manual
Suggestions for better Mod db entries
To really stand out on the modification database and to really explain your point it would be a good idea to add a few pictures of your modification in action. Taking the pictures on the default theme would be recommended so that people can understand how your mod works in context to a standard SMF install. If your modification has different features depending on who is viewing it then it would be a good idea to have a picture for each of the different roles, for example Administrators, Moderator, Member view. Pictures should ideally be screenshots that are cropped to show the new functionality.
A changelog is a good development habit to build, it shows progression of the code and helps anyone viewing your modification for the first time to see that your actively working on the modification, it's got a good history and it's build from quality code that is being reviewed and updated as bugs or issues develop.