{
  "context": "Tests whether the agent implements the specific Python invariant check patterns from the skill: Path().exists() for artifact existence, json.loads() for schema validation, time.time()-based timestamp freshness check within 300 seconds, and hashlib.sha256 for checksum matching.",
  "type": "weighted_checklist",
  "checklist": [
    {
      "name": "Path exists check",
      "description": "stage_gate.py uses Path(...).exists() or os.path.exists() to check the artifact exists",
      "max_score": 10
    },
    {
      "name": "Non-empty check",
      "description": "stage_gate.py checks the file size is greater than 0 (e.g. os.path.getsize, Path.stat().st_size, or len(content) > 0)",
      "max_score": 8
    },
    {
      "name": "JSON parse check",
      "description": "stage_gate.py uses json.loads() or json.load() to verify the file parses as valid JSON",
      "max_score": 10
    },
    {
      "name": "Timestamp freshness check",
      "description": "stage_gate.py checks (time.time() - data['timestamp']) < 300 (or equivalent: within 5 minutes using datetime)",
      "max_score": 12
    },
    {
      "name": "SHA-256 checksum",
      "description": "stage_gate.py uses hashlib.sha256(...).hexdigest() to compute and compare the checksum",
      "max_score": 12
    },
    {
      "name": "Exit code on failure",
      "description": "stage_gate.py exits with a non-zero code (sys.exit(1) or equivalent) when any check fails",
      "max_score": 8
    },
    {
      "name": "Per-check output",
      "description": "stage_gate.py prints a per-check result to stdout (pass/fail for each individual check, not just a summary)",
      "max_score": 8
    },
    {
      "name": "Conditional timestamp check",
      "description": "stage_gate.py only checks timestamp if the 'timestamp' field exists in the JSON (not unconditional)",
      "max_score": 8
    },
    {
      "name": "Contract table present",
      "description": "contract.md contains a table with boundary, invariants, and failure action columns (at minimum)",
      "max_score": 8
    },
    {
      "name": "Failure message specificity",
      "description": "stage_gate.py prints a specific failure message identifying WHICH check failed (not just 'error' or 'failed')",
      "max_score": 8
    },
    {
      "name": "Assert pattern or equivalent",
      "description": "stage_gate.py uses assert statements or explicit if/raise patterns for invariant checking (not just print warnings without exit)",
      "max_score": 8
    }
  ]
}