BC youtube-download
Download YouTube videos, playlists, audio, thumbnails, metadata, and subtitles with yt-dlp. Use when you need to fetch media from YouTube URLs, choose video/audio quality or formats, save files locally, pass cookies for private or age-restricted videos, resume downloads, or ensure yt-dlp is installed and updated before downloading.
Download YouTube videos, playlists, audio, thumbnails, metadata, and subtitles with yt-dlp.
As a process C 51/100 · Has gaps — weak spots: result and completion, when it triggers, inputs and preconditions
What is at stake
The skill contains fragments that, in the wrong hands, cost money or data. Below: what the installer risks and what the author should do.
The instructions or scripts send data out: environment variables, keys, file contents, chat history. You may never notice, because the agent performs the upload as "part of the task".
If the upload is not needed for the task, remove it: catalogs flag such skills and delist them. If it is needed, name the destination explicitly, say what leaves the machine, and give the user a switch.
How to improve
- Address the high-severity findings: each costs 18 safety points. If one is a false positive, add the rule id to guard.allow in spec.yaml.
- Your own cases (evals/evals.json, 4–6 real requests with expected answers): the full check would then run those instead of a model-drafted suite.
- A spec.yaml with trigger phrases and assertions — a behaviour contract for CI; `skilltest init` writes a template.
Guard findings · 2
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high Exfiltration
intent-browser-credential-storeSKILL.md:65Accesses a browser credential / cookie storepython3 youtube-download/scripts/youtube_download.py "URL" --cookies-from-browser chrome
Medium and low: 1
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low Exfiltration
intent-browser-credential-storescripts/youtube_download.py:179Accesses a browser credential / cookie store (security demo / example; quoted — discussed, not commanded)help="Browser name for yt-dlp cookies, for example chrome, safari, firefox, edge.",
demoquoted
Files scanned: 4. Evidence is masked. Grey chips explain why severity was lowered.
Against the Agent Skills spec
✓ No remarks against the Agent Skills spec
Process rating: all ten parameters 51/100
- 0Result and completion. Does not say what the result is
- 0Inputs and preconditions. Does not say what the process needs to start
- 0Progress reporting. Says nothing while it works
- 20When it triggers. No condition that starts the skill
- 40Consistency. Frontmatter name (youtube-download) differs from the folder (clawbus-youtube-download)
- 60Tools and files. Uses tools (python) that frontmatter does not declare
- 100Steps. 10 steps
- 100Failures and branches. 2 branches, has a failure section
- 100Execution cost. Instruction body is 725 tokens
- 100Running it twice. No mutating operations
Everything here is measured from the skill text rather than judged by a model, so the numbers are checkable. A parameter weighs more when it is a more common reason for the process to stall.
Quality signals
- +5Description has no quoted example phrases that should trigger the skill
- +4Description does not say when NOT to use the skill (false activations)
- +3Output format is not stated: the model decides each time
- +1No license
- +2Single-language instructions
- +3Description length 333: enough signal without eating the budget
- +4Structure: 5 headings
- +3Step-by-step instructions: 10 items
- +4Has examples (7 code blocks)
- +3All 1 scripts are documented
Quality base 70; lint remarks subtract, signals add up to 100. Result: 87.