| name | youtube |
| description | Download from YouTube with yt-dlp — full video, audio-only MP3, subtitles/transcript, metadata JSON, whole playlists, and thumbnails. Real yt-dlp binary (network). Binding-only in the thesis benchmark. |
YouTube Skill
Use this skill to fetch content from YouTube via the real yt-dlp binary. Because it
touches the network, it is evaluated binding-only (command correctness, no execution)
in the thesis benchmark to keep runs offline and side-effect-free. It pairs with the ffmpeg
skill for a real two-step composite (composite_youtube_to_mp3: yt-dlp → ffmpeg).
The commands below are the gold grammar; the discriminating flags distinguish the
sibling actions (all start with yt-dlp <url>).
Commands (via bash) — invoke yt-dlp directly
Download the full video (bare)
yt-dlp "<url>"
Download audio as MP3 (discriminator: -x --audio-format mp3)
yt-dlp -x --audio-format mp3 "<url>"
Fetch subtitles / transcript (discriminator: --write-auto-sub --skip-download)
yt-dlp --write-auto-sub --skip-download "<url>"
Dump metadata JSON (discriminator: --dump-json --skip-download)
yt-dlp --dump-json --skip-download "<url>"
Download a whole playlist (discriminator: --yes-playlist)
yt-dlp --yes-playlist "<playlist-url>"
Download the thumbnail (discriminator: --write-thumbnail --skip-download)
yt-dlp --write-thumbnail --skip-download "<url>"
Notes
download_video (bare) vs download_audio (-x) is a sibling pair distinguished only by
the -x flag — binding cannot assert the absence of -x, so routing carries the
discrimination for the bare-video case.download_audio collides cross-skill with the ffmpeg skill's extract_audio ("rip the
mp3"); the source (URL vs local file) is the discriminator. See the findings report.- Composite
composite_youtube_to_mp3 chains download_audio → ffmpeg transcode.
