Keeping the most critical information within the first 1-2 lines or approximately 100-200 characters is generally recommended. However, it's essential to remember that viewers may not read the entire description, so it's best to prioritize the critical information initially. Please include a brief description of your video, relevant keywords for SEO, links to related content or resources, timestamps for each section, social media handles, and any necessary disclaimers or disclosures in your YouTube description to maximize its search engine optimization.