{"tool":"isbn-check","title":"ISBN check","description":"Validate an ISBN-10 (mod-11) or ISBN-13 (1,3-weight mod-10) checksum.","method":"POST","call":"/v1/tools/isbn-check/call","input_schema":{"type":"object","required":["isbn"],"properties":{"isbn":{"type":"string","description":"ISBN-10 or ISBN-13; dashes/spaces allowed."}}},"output_schema":{"type":"object","properties":{"tool":{"type":"string"},"valid":{"type":"boolean"},"normalized":{"type":"string"},"country":{"type":"string"},"reason":{"type":"string"},"scope":{"type":"string"}},"required":["valid","reason"]},"price_usdc_floor":0.000999,"price_note":"dynamic-dutch: live quote via GET /health or the 402 challenge on POST without payment","example_request":{"input":{"isbn":"978-0-306-40615-7"}},"docs":"https://rail.akrivis.in/openapi.json","mcp":"https://rail.akrivis.in/mcp"}