{"name":"isbn_check_digit","title":"ISBN Check Digit Validator","category":"developer","description":"Validate a 10- or 13-digit ISBN's check digit (ISO 2108), or compute the check digit a 9- or 12-digit ISBN prefix would need.","price_usd":0.001,"input_schema":{"type":"object","properties":{"isbn":{"type":"string","description":"ISBN (hyphens/spaces allowed)"},"mode":{"type":"string","description":"validate | check_digit (default validate)","enum":["validate","check_digit"]}},"additionalProperties":false,"required":["isbn"]}}