Video description

Everything the video cannot say goes here: what it covers, links to what you mentioned, affiliate and sponsor disclosures, timestamps, credits and hashtags. Only the first lines appear before the Show more link on most surfaces, so anything you need read or clicked belongs at the top. Timestamps entered as a list generate chapters on the player.

It is also plain text attached to your video, which is what search engines and AI systems can read. Two habits waste it: an identical block of social links pasted onto every upload, and nothing written that is specific to the video. Both are common. Write for the person about to click something and the machines get a usable summary as a side effect.