The Intermediate YouTube Manager's Guide to Writing Video Descriptions That Build Community in Agency Using ChatGPT

You are a senior YouTube content strategist with 11 years of experience writing video descriptions, channel community systems, and subscriber retention frameworks for marketing agencies managing client YouTube channels where the video description is consistently underused as a community-building tool despite being the second-most-read piece of text on any video page. Help me write optimized video descriptions so I can build a stronger community and create a description system that consistently converts first-time viewers into subscribers and subscribers into an active commenting community. My situation: - Agency client type and YouTube channel focus: [e.g., "a B2B marketing agency managing a client's YouTube channel — client is a project management software company with 14,000 subscribers and 8 to 10 videos published monthly"] - Current description quality and community problem: [e.g., "descriptions are currently 2 to 3 sentences summarizing the video topic followed by a link to the product — average comment count is 4 per video, subscriber growth has flatlined at under 50 per month"] - Video content types published: [e.g., "product tutorials, customer case study interviews, and thought leadership pieces from the founder — tutorials get the most views, case studies get the most comments, thought leadership gets the most shares"] - Target community metric: [e.g., "want to increase average comments per video from 4 to 20 and monthly subscriber growth from 50 to 200 within 90 days"] - YouTube search and discovery context: [e.g., "most traffic comes from YouTube search for project management tutorial keywords — the descriptions are not keyword-optimized and the channel is missing traffic from related video recommendations"] - Call to action current performance: [e.g., "the product link in the description gets an average 12 clicks per video — the agency wants to test a comment-first CTA to build community before directing viewers to the product page"] - Description length and format constraint: [e.g., "client requires the product name mentioned in the first two sentences and the website URL in the first three lines — all other description elements are at the agency's discretion"] Deliver: 1. A video description template for three video types — tutorial description (keyword-rich opening paragraph that includes the primary search term in the first sentence, a four-bullet chapter breakdown, a community question that relates directly to the tutorial topic, and the product link in context rather than as a standalone URL), case study description (the specific outcome number from the case study in the opening sentence, a three-sentence client background, a community question asking viewers about their own equivalent challenge, and the subscriber CTA before the product link), and thought leadership description (the core argument in the first sentence, the three questions the video answers formatted as a preview list, a comment prompt that invites viewers to share their own perspective, and the related content section linking to two previous videos) 2. A community question formula for 10 video topics — a fill-in-the-blank format that produces a comment-driving question for each of the client's recurring video categories, with the question type matched to the content (tutorial: specific application question, case study: peer comparison question, thought leadership: opinion solicitation question) 3. A keyword optimization structure for the description opening paragraph — the placement of the primary search term (first 25 words), the supporting keyword (second sentence), and the related terms (body of the description), with a completed example using a project management software tutorial topic and the keyword density recommendation that avoids over-optimization 4. A chapter timestamp format brief — the exact format for YouTube chapter markers (MM:SS Chapter Title, maximum 30 characters per title), the recommended number of chapters for videos under 10 minutes versus over 10 minutes, and the first chapter title formula that doubles as a keyword signal for YouTube's recommendation algorithm 5. A subscriber CTA placement test — two CTA versions to A/B test across the next 10 videos, covering a CTA that appears before the product link (community-first approach) and a CTA that appears after the product link (conversion-first approach), with the metric used to determine which approach produces more subscribers per 1,000 views 6. A community pinned comment brief — a template for the agency to post as a pinned comment within the first 30 minutes of each video going live, covering the community question format, the channel creator's personal response to the question as a seed comment, and the reply format for the first five viewer responses that models the commenting culture the channel wants to establish 7. A description performance tracking system — a Google Sheets template tracking six metrics per video for 30 days after publication (click-through rate from thumbnail, average view duration, comment count, subscriber gain from the video, product link clicks, and the community question response rate), with the comparison formula that identifies which description elements correlate with higher comment counts and subscriber gains 8. A 90-day description improvement roadmap — a phased implementation plan covering the template rollout in weeks one and two, the community question formula applied to the existing 10 most-viewed videos in weeks three and four, the chapter timestamp addition to all videos in weeks five and six, and the subscriber CTA A/B test in weeks seven through twelve, with the target metric at each phase that confirms the community-building approach is working before moving to the next phase **Write every description template and community question formula assuming the agency account manager is briefing a junior copywriter who has never written for YouTube — every template must produce a usable description draft without a follow-up briefing call, and every formula must explain the platform-specific logic behind the element so the copywriter makes better judgment calls when the brief does not cover a specific video topic.**