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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.

67

Quality

81%

Does it follow best practices?

Impact

No eval scenarios have been run

SecuritybySnyk

Risky

Do not use without reviewing

SKILL.md
Quality
Evals
Security

Quality

Content

62%

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

This skill is highly actionable with excellent workflow clarity, providing executable commands, clear multi-step processes, and comprehensive error recovery paths. However, it is significantly over-verbose with substantial redundancy across sections (the non-technical UX flow, SOP, and agent checklist repeat similar troubleshooting logic), unnecessary explanations of concepts Claude already knows (ffmpeg parameters, HLS basics), and inline content that should be in reference files.

Suggestions

Consolidate the 'Non-Technical User Experience', 'Reliable Download SOP', and 'Agent Execution Checklist' sections into a single workflow section to eliminate redundant troubleshooting and fallback logic that appears in all three.

Remove explanations of concepts Claude already knows — e.g., what CRF values mean, what AAC is, what HLS playlists are, what `-c copy` does — and keep only the specific flags/values to use.

Move the HLS stream download section and WebM-to-MP4 conversion details into separate reference files (e.g., `references/hls-downloads.md`, `references/format-conversion.md`) and link to them from the main skill.

Remove the 'When to Use This Skill' section entirely — this duplicates the frontmatter description and wastes tokens on information that should be in metadata, not the skill body.

DimensionReasoningScore

Conciseness

The skill is extremely verbose at ~350+ lines. It explains concepts Claude already knows (what HLS is, what ffmpeg parameters do, what AAC is), includes unnecessary sections like 'When to Use This Skill' (redundant with frontmatter description), explains ffmpeg CRF values, and has significant redundancy between the 'Non-Technical User Experience', 'Agent Execution Checklist', and 'Reliable Download SOP' sections which repeat the same troubleshooting logic multiple times.

1 / 3

Actionability

The skill provides fully executable, copy-paste-ready commands throughout — yt-dlp format selection, ffmpeg conversion, HLS downloads with headers, and a bundled script with comprehensive argument documentation. Concrete examples cover all major use cases with specific flags and expected outputs.

3 / 3

Workflow Clarity

Multi-step workflows are clearly sequenced with explicit validation checkpoints (e.g., verify yt-dlp version → check formats → install PO token → verify formats again → download → verify resolution with ffprobe). Error recovery paths are well-defined with specific fallback chains (PO token → cookies → Android client) and the troubleshooting section maps symptoms to solutions systematically.

3 / 3

Progressive Disclosure

The skill references `references/po-token-setup.md` and `scripts/download_video.py` appropriately, but the main file itself is monolithic with too much inline content. The HLS section, WebM conversion details, and the extensive troubleshooting could be split into separate reference files. The non-technical UX section, SOP, and agent checklist have overlapping content that could be consolidated or separated.

2 / 3

Total

9

/

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 clearly defines its scope, lists concrete actions and tools, includes a well-structured 'Use when' clause with diverse trigger scenarios, and uses natural keywords users would employ. The description is specific enough to avoid conflicts while being comprehensive enough to cover the full range of video downloading use cases.

DimensionReasoningScore

Specificity

Lists multiple specific concrete actions: downloading YouTube videos, HLS streams (m3u8), extracting audio, handling protected streams with authentication headers, and troubleshooting specific issues like nsig extraction failures, 403 errors, and cookie extraction problems.

3 / 3

Completeness

Clearly answers both what ('Download YouTube videos and HLS streams using yt-dlp and ffmpeg') and when ('Use this skill when users request downloading videos, extracting audio, handling protected streams...or troubleshooting download issues') with explicit trigger scenarios.

3 / 3

Trigger Term Quality

Excellent coverage of natural terms users would say: 'YouTube', 'download videos', 'HLS streams', 'm3u8', 'yt-dlp', 'ffmpeg', 'Mux', 'Vimeo', 'extracting audio', '403 errors', 'cookie extraction', 'authentication headers'. These are terms users would naturally use when seeking help with video downloading.

3 / 3

Distinctiveness Conflict Risk

Highly distinctive with a clear niche around video downloading via yt-dlp/ffmpeg, specific platforms (YouTube, Mux, Vimeo), specific protocols (HLS/m3u8), and specific error types. Unlikely to conflict with other skills.

3 / 3

Total

12

/

12

Passed

Validation

90%

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

Validation10 / 11 Passed

Validation for skill structure

CriteriaDescriptionResult

skill_md_line_count

SKILL.md is long (509 lines); consider splitting into references/ and linking

Warning

Total

10

/

11

Passed

Repository
daymade/claude-code-skills
Reviewed

Table of Contents

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