How do you submit Mac apps to the directory on a Mac?

What do you mean? Just go to the applevis homepage and click submit content, then mac app directory then follow the prompts. If this is not what you mean can you be a bit more clear in your question so we may help troubleshoot/

Thanks.

You should be able to just shift down arrow on the description. If that does not work, open the store link in safari by coppying the link then pasting it in the address bar then down arrowing through the description and selecting by holding down shift down arrows. For example here is an excerpt of one of the apps I bought recently.

** 2015 APPLE DESIGN AWARD WINNER **

Designed exclusively for OS X Yosemite and El Capitan, Fantastical 2 includes powerful features such as an incredibly intuitive parsing engine, a full calendar window (with day, week, month, and year views), a quick access mini window, iCloud reminders support, time zone support, and much, much more.

Make sure you have quick nav turned off when copying html content. It is way too complicated trying to do it with quick nav turned on.

Try going to the description of the app, once voiceover is on the description, press command c to copy the description, or press VO-Shift-C to copy the last spoken phrase to the clipboard. This will copy the entire description. Hope this helps.