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name: thumbnail-designer description: Generate thumbnail design concepts and specifications. Use when creating visuals for YouTube or blogs. allowed-tools: Write

Thumbnail Designer

Version: 1.0.0 Purpose: Create thumbnail design specs

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Workflow

Step 1: Understand Context

Ask:

• Platform? (YouTube, Blog, SNS)
• Topic?
• Target emotion? (curiosity, urgency, trust)

Step 2: Generate Concepts

Provide 3 concepts:

Copy## Concept 1: [Name]

**Layout**: [Left/Center/Right focus]
**Main Text**: "[3-5 words]"
**Sub Text**: "[Optional]"
**Image**: [Description]
**Colors**: [Primary, Secondary, Accent]
**Emotion**: [Target feeling]

Step 3: Specification

Copysize: 1280x720 (YouTube) / 1200x630 (OGP)
format: PNG
text:
  font: "Noto Sans JP Bold"
  size: 72px
  color: "#FFFFFF"
  shadow: true
background:
  type: gradient / image
  colors: ["#1a1a2e", "#16213e"]

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Best Practices

• 3 words max for main text
• High contrast colors
• Face close-up increases CTR
• Avoid small text (unreadable on mobile)