{
  "id": "rule-null-check-001",
  "name": "Null Check - Email Column",
  "description": "Ensures email column has less than 5% null values",
  "ruleType": "NULL_CHECK",
  "datasetId": "dataset-customers-001",
  "columnName": "email",
  "threshold": 5.0,
  "severity": "HIGH",
  "enabled": true,
  "createdAt": "2024-01-01T00:00:00Z"
}