youtube-downloader

Download YouTube videos and HLS streams (m3u8) from platforms like Mux, Vimeo, etc. using yt-dlp and ffmpeg. Use this skill when users request downloading videos, extracting audio, handling protected streams with authentication headers, or troubleshooting download issues like nsig extraction failures, 403 errors, or cookie extraction problems.

1.59x

Quality

88%

Does it follow best practices?

Impact

78%

1.59x

Average score across 3 eval scenarios

Securityby

Risky

Do not use without reviewing

Quality

Content

77%

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

This is a comprehensive and highly actionable skill with excellent workflow clarity and concrete executable examples. The main weaknesses are verbosity (particularly in the non-technical user experience section and some redundant troubleshooting content) and the monolithic structure that could benefit from splitting detailed sections into reference files.

Suggestions

Move the detailed HLS stream section to a separate reference file (e.g., references/hls-downloads.md) and link to it from the main skill

Consolidate the troubleshooting sections - there's overlap between 'Troubleshooting Quick Reference' and error handling mentioned in the SOP/checklist

Trim the 'Non-Technical User Experience' section - Claude understands how to interact with users; focus on the specific choices and defaults rather than explaining interaction patterns

Dimension	Reasoning	Score
Conciseness	The skill contains useful information but is verbose in places, with some redundancy between sections (e.g., troubleshooting items repeated, multiple explanations of PO token setup). The 'Non-Technical User Experience' section explains interaction patterns Claude should already understand.	2 / 3
Actionability	Provides fully executable commands throughout with specific examples for yt-dlp, ffmpeg, and the bundled script. Commands are copy-paste ready with clear parameter explanations and concrete output expectations.	3 / 3
Workflow Clarity	Multi-step processes are clearly sequenced with explicit validation checkpoints (verify installation, check formats, verify download quality). The SOP and Agent Execution Checklist provide clear error recovery paths and feedback loops for common failures.	3 / 3
Progressive Disclosure	References external files appropriately (references/po-token-setup.md) but the main document is quite long with content that could be split out. The HLS section and troubleshooting could be separate reference files to keep the main skill leaner.	2 / 3
	Total	10 / 12 Passed

Description

100%

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

This is an excellent skill description that hits all the marks. It provides specific capabilities (downloading, extracting, troubleshooting), names concrete tools and platforms, includes a comprehensive 'Use this skill when...' clause with natural trigger terms, and is distinctive enough to avoid conflicts with other skills. The inclusion of specific error types (nsig extraction failures, 403 errors, cookie extraction problems) is particularly valuable for routing troubleshooting requests.

Dimension	Reasoning	Score
Specificity	Lists multiple specific concrete actions: 'Download YouTube videos', 'HLS streams (m3u8)', 'extracting audio', 'handling protected streams with authentication headers', 'troubleshooting download issues'. Also names specific tools (yt-dlp, ffmpeg) and platforms (Mux, Vimeo).	3 / 3
Completeness	Clearly answers both what (download videos, extract audio, handle protected streams, troubleshoot issues) AND when with explicit 'Use this skill when...' clause listing specific trigger scenarios including error types.	3 / 3
Trigger Term Quality	Excellent coverage of natural terms users would say: 'YouTube videos', 'HLS streams', 'm3u8', 'Mux', 'Vimeo', 'yt-dlp', 'ffmpeg', 'downloading videos', 'extracting audio', 'nsig extraction failures', '403 errors', 'cookie extraction'. These are terms users would naturally use when seeking help.	3 / 3
Distinctiveness Conflict Risk	Highly distinctive with clear niche: video downloading specifically via yt-dlp/ffmpeg, with platform-specific mentions (YouTube, Mux, Vimeo) and technical error types (nsig, 403, cookies). Unlikely to conflict with general media or file handling skills.	3 / 3
	Total	12 / 12 Passed

Validation

100%

Warnings & errors only

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 11 / 11 Passed

Validation for skill structure

No warnings or errors.

Repository: fernandezbaptiste/claude-code-skills
Commit: 4f0eae8

Reviewed: 4 months ago

Table of Contents

Discovery Implementation Validation

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.