Below are the steps to take to add a description to your YouTube Shorts videos:

On Mobile Devices & Phones:

1. Open the YouTube app and login to your channel.

2. Click Library from the menu bar at the bottom of the screen then click Your videos.

3. Find the Shorts video you would like to add a description to and click the three dots listed next to the video.

4. Click Edit.

5. Click on the section that says Description - this is where you will want to add your video description!

6. Return to the previous page and click Save at the top of the screen to save your edits.

On Computers:

1. Open YouTube and login to your channel.

2. Navigate to your YouTube Studio and click the Content tab to load all of your videos.

3. Find the Shorts video you would like to add a description to and click the edit icon listed underneath the video title.

4. Click the Description section and enter your video description here.

5. Click Save at the top of the screen to save your edits.

That's it! Keep in mind that YouTube Shorts descriptions are limited to 5000 characters.