DC youtube-downloader
Fetch existing YouTube transcripts/subtitles or archive spoken video content as text, and download YouTube videos/audio or HLS streams (m3u8) with yt-dlp and ffmpeg. Use for transcript/subtitle retrieval, text-first video archiving, video/audio downloads, protected streams with authentication headers, and download failures including nsig, 403 or browser-cookie issues.
Fetch existing YouTube transcripts/subtitles or archive spoken video content as text, and download YouTube videos/audio or HLS streams (m3u8) with yt-dlp and…
As a process C 57/100 · Has gaps — References files that are not bundled: URL, THUMBNAIL_URL
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.
- The SKILL.md body is over 5,000 tokens: move reference detail into references/ and load it when needed.
- The text references files that are not there: add them or drop the references.
- 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 · 6
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high Exfiltration
intent-browser-credential-storereferences/po-token-setup.md:163Accesses a browser credential / cookie storeyt-dlp --cookies-from-browser chrome "VIDEO_URL"
-
high Exfiltration
intent-browser-credential-storeSKILL.md:186Accesses a browser credential / cookie storeyt-dlp --cookies-from-browser chrome -f "bestvideo[height<=1080]+bestaudio/best" "VIDEO_URL"
Medium and low: 4
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medium Exfiltration
intent-browser-credential-storeSKILL.md:413Accesses a browser credential / cookie store (quoted — discussed, not commanded)**Symptom**: `Extracting cookies from chrome` hangs indefinitely.
quoted -
low Exfiltration
intent-browser-credential-storescripts/download_video.py:747Accesses a browser credential / cookie store (security demo / example; quoted — discussed, not commanded)cookies_from_browser: Load cookies from browser (e.g., chrome, firefox)
demoquoted -
low Exfiltration
intent-browser-credential-storescripts/download_video.py:988Accesses a browser credential / cookie store (security demo / example; quoted — discussed, not commanded)help="Load cookies from browser (e.g., chrome, firefox)",
demoquoted -
low Exfiltration
intent-browser-credential-storeSKILL.md:297Accesses a browser credential / cookie store (security demo / example; quoted — discussed, not commanded)- `--cookies-from-browser` - Load cookies from a browser (e.g., chrome, firefox)
demoquoted
Files scanned: 5. Evidence is masked. Grey chips explain why severity was lowered.
Against the Agent Skills spec
- warning
body-longSKILL.md body ≈ 5009 tokens (recommended < 5000); move details to references/ - warning
missing-refreference to a missing file: URL - warning
missing-refreference to a missing file: THUMBNAIL_URL
Process rating: all ten parameters 57/100
- 0Tools and files. 2 referenced file(s) missing: URL, THUMBNAIL_URL
- 0Result and completion. Does not say what the result is
- 70When it triggers. States when to use, but not when not to
- 70Inputs and preconditions. Inputs and preconditions are listed
- 70Execution cost. Instruction body is 5009 tokens
- 85Steps. 109 steps, 2 vague phrases
- 100Failures and branches. 4 branches, has a failure section
- 100Consistency. Name and required fields are in place
- 100Running it twice. Mutating operations check current state
- 100Progress reporting. Reports progress
- low 16 top-level sections: this looks like several domains in one skill
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
- -2localhost URLs: will not work for another user
- +1No license
- +2Single-language instructions
- +3Description length 370: enough signal without eating the budget
- +4Structure: 46 headings
- +3Step-by-step instructions: 109 items
- +4Has examples (21 code blocks)
- +4Reference files are cited in the instructions (3 of 3)
- +3All 1 scripts are documented
Quality base 70; lint remarks subtract, signals add up to 100. Result: 70.