youtube-thumbnail

youtube-thumbnail is a skill for Claude Code from charlie947/social-media-skills. It costs 99 tokens per session (1,243 once invoked), scanned A, original, MIT.

A workflow for creating branded YouTube thumbnail image prompts from a video title, a creator reference photo, and brand colours.

In plain words
What is it for?
It helps prepare thumbnail prompts for Gemini, including the video title, creator image, emotional tone, and brand styling.
Why use it?
It removes the need to plan the thumbnail concept and visual direction from scratch while keeping thumbnails recognisable across videos.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: names the AskUserQuestion tool.

Part of the social-media-skills plugin — 17 skills shipped together

Good fit It helps prepare thumbnail prompts for Gemini, including the video title, creator image, emotional tone, and brand styling.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/charlie947/social-media-skills/youtube-thumbnail
About the project

charlie947/social-media-skills is a collection of markdown instructions that gives AI agents specialized workflows for creating and managing social-media content. It supports a content system spanning LinkedIn, Instagram, Substack, X, and YouTube, with shared voice and context files guiding the individual skills.

charlie947/social-media-skills · 3,385 stars · on GitHub

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add charlie947/social-media-skills --skill youtube-thumbnail
Clone the repo
git clone --depth 1 https://github.com/charlie947/social-media-skills

Made for: Claude Code.

Or install social-media-skills, the plugin that ships this one along with the rest of its 17 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for youtube-thumbnail

README.md
[![agentmods](https://agentmods.dev/badge/skills/charlie947/social-media-skills/youtube-thumbnail/github.svg)](https://agentmods.dev/skills/charlie947/social-media-skills/youtube-thumbnail)
Your own site
<a href="https://agentmods.dev/skills/charlie947/social-media-skills/youtube-thumbnail"><img src="https://agentmods.dev/badge/skills/charlie947/social-media-skills/youtube-thumbnail/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for youtube-thumbnail

Your own site · 80×15
<a href="https://agentmods.dev/skills/charlie947/social-media-skills/youtube-thumbnail"><img src="https://agentmods.dev/badge/skills/charlie947/social-media-skills/youtube-thumbnail.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 99 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,243 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • Socket pass 28 Apr 2026
  • Snyk pass 28 Apr 2026
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00099 $0.01243
Opus 5 $0.00049 $0.00622
Sonnet 5 $0.00020 $0.00249
Haiku 4.5 $0.00010 $0.00124

Measured 13d ago against content hash 8a14346d43a0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

youtube-thumbnail scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 13d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

skills/youtube-thumbnail/SKILL.md · 133 lines

How it starts

The opening of the file, as written. The whole thing — 133 lines — stays where its author put it; the contents beside it link to each section on GitHub.

YouTube Thumbnail

CRITICAL: Auto-start on load

When this skill triggers, go straight to Step 1.

Step 1. Gather inputs

Check the project for a reference photo config. Look in this order:

  1. thumbnail-config.md in the project root
  2. brand-kit.md — look for a reference image path and brand colours
  3. about-me.md — for the creator's name and positioning

If a reference photo path is stored, pre-fill it. Otherwise ask:

Upload or provide the path to the reference photo of yourself you want used in the thumbnail. Ideally a clear headshot with distinctive lighting and expression you plan to reuse across videos for brand consistency.

Then call AskUserQuestion:

[
  {
    "question": "What is the video title?",
    "header": "Title",
    "multiSelect": false,
    "options": [
      {"label": "I will type the title", "description": "Type the full working title"},
      {"label": "Suggest one", "description": "Given the topic, propose 3 click-worthy titles first"}
    ]
  },
  {
    "question": "Emotional tone?",
    "header": "Tone",
    "multiSelect": false,
    "options": [
      {"label": "Shock / surprise", "description": "Wide eyes, open mouth, bold reaction"},
      {"label": "Curious / thinking", "description": "Slight smirk, raised eyebrow, gaze off-frame"},
      {"label": "Confident / direct", "description": "Eye contact, calm, assertive"},
      {"label": "Frustrated / strong take", "description": "Intense gaze, hand gesture, tension"}
    ]
  }
]

Step 2. Apply thumbnail best practices

Every thumbnail must follow these rules:

  • Face fills 30 to 50 percent of the frame. Readable at small sizes.
  • 3 to 5 words maximum of large text. 6 if absolutely necessary.
  • Two colours dominate. Brand primary + one high-contrast accent (yellow, red, cyan work well).
  • One clear focal element besides the face. Tool logo, bold number, arrow, or prop.
  • High contrast between face, text, and background. Test by squinting.
  • Text is not a sentence. It is a hook phrase. Examples: "I fired my team", "Claude can now...", "Don't do this".
  • No small text, no logos bottom-right (watch time icon sits there).

Read the full file on GitHub · 133 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 13d ago First seen · 133 lines · 99 tokens per session scan A 8a14346d43a0

Subscribe to this mod's changes

youtube-thumbnail is a skill published in the GitHub repository charlie947/social-media-skills (3,385 stars, last pushed 13d ago), licensed MIT. It adds 99 tokens to every session and 1,243 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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