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.
npx skills add bcastelino/agent-skills-kit --skill youtube-summarizergit clone --depth 1 https://github.com/bcastelino/agent-skills-kitWrote 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.
[](https://agentmods.dev/skills/bcastelino/agent-skills-kit/youtube-summarizer)<a href="https://agentmods.dev/skills/bcastelino/agent-skills-kit/youtube-summarizer"><img src="https://agentmods.dev/badge/skills/bcastelino/agent-skills-kit/youtube-summarizer/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.
<a href="https://agentmods.dev/skills/bcastelino/agent-skills-kit/youtube-summarizer"><img src="https://agentmods.dev/badge/skills/bcastelino/agent-skills-kit/youtube-summarizer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00032 | $0.02736 |
| Opus 5 | $0.00016 | $0.01368 |
| Sonnet 5 | $0.00006 | $0.00547 |
| Haiku 4.5 | $0.00003 | $0.00274 |
Grade A, and why
youtube-summarizer 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 9d 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.
How it starts
The opening of the file, as written. The whole thing — 404 lines — stays where its author put it; the contents beside it link to each section on GitHub.
youtube-summarizer
Purpose
This skill extracts transcripts from YouTube videos and generates comprehensive, verbose summaries using the STAR + R-I-S-E framework. It validates video availability, extracts transcripts using the youtube-transcript-api Python library, and produces detailed documentation capturing all insights, arguments, and key points.
The skill is designed for users who need thorough content analysis and reference documentation from educational videos, lectures, tutorials, or informational content.
When to Use This Skill
This skill should be used when:
- User provides a YouTube video URL and wants a detailed summary
- User needs to document video content for reference without rewatching
- User wants to extract insights, key points, and arguments from educational content
- User needs transcripts from YouTube videos for analysis
- User asks to "summarize", "resume", or "extract content" from YouTube videos
- User wants comprehensive documentation prioritizing completeness over brevity
Step 0: Discovery & Setup
Before processing videos, validate the environment and dependencies:
# Check if youtube-transcript-api is installed
python3 -c "import youtube_transcript_api" 2>/dev/null
if [ $? -ne 0 ]; then
echo "⚠️ youtube-transcript-api not found"
# Offer to install
fi
# Check Python availability
if ! command -v python3 &>/dev/null; then
echo "❌ Python 3 is required but not installed"
exit 1
fi
Ask the user if dependency is missing:
youtube-transcript-api is required but not installed.
Would you like to install it now?
- [ ] Yes - Install with pip (pip install youtube-transcript-api)
- [ ] No - I'll install it manually
If user selects "Yes":
pip install youtube-transcript-api
Verify installation:
python3 -c "import youtube_transcript_api; print('✅ youtube-transcript-api installed successfully')"
Main Workflow
Progress Tracking Guidelines
Throughout the workflow, display a visual progress gauge before each step to keep the user informed. The gauge format is:
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 9d ago First seen · 404 lines · 32 tokens per session scan A 5232b284d17d
youtube-summarizer is a skill published in the GitHub repository bcastelino/agent-skills-kit (2 stars, last pushed 1mo ago), licensed MIT. It adds 32 tokens to every session and 2,736 once invoked, about $0.0002 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 2026-09-03.
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