AC Skill Scanner
Pre-install security scanner for ClawHub skills. Analyzes any SKILL.md for prompt injection, data exfiltration patterns, malicious bash commands, typosquatting, and quality red flags before you install. Given that 13%+ of ClawHub skills have been flagged for security issues, scan before you install. Triggers on "scan skill", "audit skill", "is this skill safe", "check skill security", "/skill-scanner".
As a process C 61/100 · Has gaps — weak spots: inputs and preconditions, consistency, progress reporting
How to improve
- 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
✓ No critical or high findings
Medium and low: 6
✓ Guard found no suspicious behaviour. 6 matches are attack strings quoted in this security skill's own documentation.
Files scanned: 2. Evidence is masked. Grey chips explain why severity was lowered.
Against the Agent Skills spec
- warning
name-formatname should be kebab-case (lowercase letters, digits, hyphens) - note
frontmatter-keyunknown frontmatter key "homepage"
Process rating: all ten parameters 61/100
- 0Inputs and preconditions. Does not say what the process needs to start
- 0Progress reporting. Says nothing while it works
- 40Consistency. Frontmatter name (Skill Scanner) differs from the folder (phy-skill-scanner)
- 50Failures and branches. 0 branches, has a failure section
- 60Tools and files. Uses tools (bash, web) 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
- 100Steps. 53 steps
- 100Execution cost. Instruction body is 2216 tokens
- 100Running it twice. Mutating operations check current state
- low 11 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
- +4Description does not say when NOT to use the skill (false activations)
- -213 emoji in the instructions: noise for the model
- +2Single-language instructions
- +5Description quotes 5 example trigger phrases
- +3Description length 405: enough signal without eating the budget
- +4Structure: 19 headings
- +3Step-by-step instructions: 53 items
- +3Output format is stated explicitly
- +4Has examples (8 code blocks)
- +1License stated
Quality base 70; lint remarks subtract, signals add up to 100. Result: 85.