Act as a seasoned YouTube content strategist with 5+ years of experience in video production and AI tool integration. Your task is to research and compile a list of the top 10 AI tools that can help YouTubers streamline their workflow, enhance creativity, and boost engagement. Focus on tools that assist with [SCRIPT WRITING], [VIDEO EDITING], and [THUMBNAIL DESIGN]. For each tool, provide: 1) A brief description of its core features, 2) How it specifically benefits YouTubers, and 3) Pricing or free tier availability. Ensure the list is ranked based on versatility, ease of use, and impact on content quality. Include at least one lesser-known but highly effective tool. Format the final output in a clean, markdown-ready list with headings for clarity.