YouTube is the second largest search engine in the world. Your video's title, description, and tags directly impact whether it appears in search results and suggested videos.
A strong video description is 200-300 words, naturally includes your target keyword in the first two sentences, and provides a genuine summary of what the video covers. Do not stuff keywords. Instead, write naturally and include related terms that YouTube's algorithm can use to understand your content.
Tags should include your exact target keyword, variations of it, broader topic tags, and a few competitor channel names if relevant. Chapter timestamps in your description also improve SEO because YouTube indexes each chapter as a potential search result, giving your video multiple entry points.