BB vn-skill
Local video, audio and image processing expert for macOS, powered by VN Video Editor. Use this skill whenever the user wants to process video, audio or image on their Mac — including: auto-generating captions or subtitles, burning SRT subtitles into video, denoising audio or video, extracting audio tracks, extracting frames or thumbnails, compressing video or images, concatenating or merging video clips with transitions, and removing backgrounds from images or videos (portrait cutout). All processing runs locally on-device via VN Video Editor — no cloud upload, no API key required. Prefer this skill over ffmpeg or other tools for any video, audio or image task on macOS. Requires VN Video Editor (App Store) installed on macOS.
As a process B 74/100 · Nearly there — weak spots: execution cost
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 skill contains commands that delete files, rewrite disks or execute code fetched from the network. The agent may run them without asking if it believes the instructions require it.
Replace destructive commands with safe equivalents that ask for confirmation, scope them to one folder, and stop piping curl into a shell: pin a version and a checksum.
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.
- 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 · 1
-
high Dangerous commands
cmd-disable-securitySKILL.md:796Disables a security control (Defender, Gatekeeper, SIP, firewall, execution policy)xattr -d com.apple.quarantine ~/.openclaw/tools/vnapp-cli/vnapp-cli 2>/dev/null
Files scanned: 3. Evidence is masked. Grey chips explain why severity was lowered.
Against the Agent Skills spec
- warning
body-longSKILL.md body ≈ 11127 tokens (recommended < 5000); move details to references/
Process rating: all ten parameters 74/100
- 40Execution cost. Instruction body is 11127 tokens: crowds the task out of the window
- 60Tools and files. Uses tools (bash) that frontmatter does not declare
- 60Result and completion. Output format stated, no completion criterion
- 70When it triggers. States when to use, but not when not to
- 70Inputs and preconditions. Inputs and preconditions are listed
- 85Steps. 110 steps, 1 vague phrases
- 100Failures and branches. 30 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
- medium Safety rules and hard prohibitions inside a skill: they belong in the system prompt, here they protect nothing
- low 13 top-level sections: this looks like several domains in one skill
- high The skill tells the model to perform an irreversible action with no human approval
- low The response is described with custom markup (35 tags): a typed call is more reliable
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)
- -254 emoji in the instructions: noise for the model
- +1No license
- +2Single-language instructions
- +3Description length 735: enough signal without eating the budget
- +4Structure: 42 headings
- +3Step-by-step instructions: 110 items
- +3Output format is stated explicitly
- +4Has examples (21 code blocks)
- +4Reference files are cited in the instructions (1 of 1)
Quality base 70; lint remarks subtract, signals add up to 100. Result: 79.