| name | thumbnail-concept |
| description | Generate high-CTR thumbnail concepts for a video — layout, focal subject, text overlay (≤4 words), color/contrast, and an image-gen prompt. Use when designing a YouTube/short thumbnail, asked for 'thumbnail ideas', or planning cover art for a video. |
| version | 0.1.0 |
| domain | media |
| tags | ["thumbnail","design","youtube","cover","ctr"] |
Thumbnail Concept
A video topic → several high-CTR thumbnail concepts with image-gen prompts.
Purpose
The thumbnail decides whether good content gets watched. This skill produces a
few distinct, honest, high-contrast thumbnail concepts — each with a layout, a
short text overlay, a color logic, and a ready image-generation prompt — so the
creator can pick and generate quickly.
When it fires
- Keyword triggers:
thumbnail, cover art, thumbnail ideas, ctr,
video cover
- File triggers:
thumbnails/**
- Command triggers:
/thumbnail-concept
Inputs
| Input | Required | Notes |
|---|
topic | yes | Video subject + the promise. |
subject | no | Hero image/asset (e.g. a nebula, a rocket). |
count | no | Number of concepts, default 3. |
Workflow
- Find the visual hook — the single image idea that conveys the promise. ✅ Check: readable at small size.
- Per concept: layout (subject placement, rule-of-thirds), overlay text
(≤4 words, high contrast), color/contrast logic, and emotional read.
- Honesty check — the thumbnail must match the actual content (no bait).
- Image-gen prompt — a concrete prompt to produce the background/subject;
if using NASA imagery, note the rights step.
Output contract
{
"concepts": [{
"layout": "string",
"overlay_text": "string — ≤4 words",
"color_logic": "string",
"emotional_read": "string",
"image_prompt": "string"
}]
}
Tools & MCP
- Tools:
Read. MCP: optional image-gen MCP.
Quality bar
Example
Input: "Why Webb sees what Hubble can't" → 3 concepts, each with a 2–3 word
overlay, contrast logic, and an image prompt.
Built on SIP — Starlight Intelligence Protocol
Substrate: starlightintelligence.org/protocol v1.1.0
Layers used: [file-contract, attestation, sovereignty]
Vertical: starlight-agent-skills · portable capability layer
