I made a stylesheet for YouTube that automatically expands the description
box under the video for you so you don't have to do it manually every time by
editing the page.
To use it, first install Stylish.
https://trisquel.info/en/browser/addons/stylish
After restarting your browser, open the Add-ons Manager and navigate to the
User Styles tab.
Click the "Write New Style" button and paste the contents of this file
(https://notabug.org/ssdclickofdeath/descriptiontube/raw/master/descriptiontube.css)
into the code editor.
You will need to manually name the script "DescriptionTube" in the small text
box above. Click on the save button, and the script should now be active.
Here is the link to the NotABug.org page.
https://notabug.org/ssdclickofdeath/descriptiontube