I accomplish this in my channel by using the '
longDescription' field in the Json item feed. I then define a playlist called "New this month" that displays at the top of my channel. It includes all new videos for the month. When a viewer selects a video that uses the 'longDescription' field they will see a "long" description of the video. If the video description does not fit on the screen, they can press the "*" key to display its contents.
Windows desktop software for creating and managing MRSS, JSON, and FireTV feeds @ https://rrirower.wixsite.com/software. No Programming, JSON or MRSS knowledge required.