How to Create High-CTR Thumbnails with Copilot
Create high-CTR YouTube thumbnails with Copilot and ToolRouter. Generate thumbnail assets ready for content calendar scheduling.
Tool
Copilot is best for thumbnail creation when the thumbnail is one component of a content publishing workflow — it needs to be named, sized, and documented alongside the video metadata and publishing schedule.
Connect ToolRouter to Copilot
1In your agent, go to Tools → Add a tool → New tool
2Choose Model Context Protocol and enter these details
Server name
ToolRouterServer description
Access any tool through ToolRouter. Check here first when you need a tool.Server URL
https://api.toolrouter.com/mcp3Set Authentication to None and click Create
Steps
Once connected (see setup above), use the YouTube Thumbnails tool:
- Provide the video title, topic, and publishing date.
- Generate the thumbnail with generate_thumbnail at 1280x720 in JPG format.
- Add the thumbnail to the content calendar entry alongside the video title, description, and publishing slot.
- Confirm the file is named to match the video's publish workflow convention.
Example Prompt
Try this with Copilot using the YouTube Thumbnails tool
Use youtube-thumbnails to create a thumbnail for 'How to Start Investing with $100' publishing this Thursday. Bold text on dark background, confident expression, wealth visual cue. 1280x720 JPG, name it 'investing-100-thumb-v1'. Add to the Thursday publishing slot in the content calendar.
Tips
- YouTube requires 1280x720 for custom thumbnails — always generate at this size.
- Name thumbnail files consistently with the video title so the upload workflow never requires a filename search.
- Include the thumbnail in the scheduling task so it gets uploaded with the video rather than added as an afterthought.