skill-scanner

Skill Security Scanner

Scan agent skills for security issues before adoption. Detects prompt injection, malicious code, excessive permissions, secret exposure, and supply chain risks.

Important: Run all scripts from the repository root using the full path via ${CLAUDE_SKILL_ROOT}.

When to Use

• You need to evaluate a skill for prompt injection, malicious code, over-broad permissions, or supply-chain risk before adopting it.
• You want a static scan plus manual review workflow for a skill directory.
• The task is to decide whether a skill is safe enough to trust in an agent environment.

Bundled Script

scripts/scan_skill.py

Static analysis scanner that detects deterministic patterns. Outputs structured JSON.

uv run ${CLAUDE_SKILL_ROOT}/scripts/scan_skill.py <skill-directory>

Returns JSON with findings, URLs, structure info, and severity counts. The script catches patterns mechanically — your job is to evaluate intent and filter false positives.

Workflow

Phase 1: Input & Discovery

Determine the scan target:

• If the user provides a skill directory path, use it directly
• If the user names a skill, look for it under plugins/*/skills/<name>/ or .claude/skills/<name>/
• If the user says "scan all skills", discover all */SKILL.md files and scan each

Validate the target contains a SKILL.md file. List the skill structure: