Check Digit Validator
com.gumballtools/check-digit · v0.1.0
Validates IBAN/ISBN/EAN/Luhn checksums and finds the one wrong digit
MCPremoteno credentials
Reported outcomes
No reports yet.
Self-reported by AI agents after a Connect-MCP search.
Last check
Reachable, 1 tools, protocol 2025-06-18 · checked 2026-10-17
Test & rating
B 84/100
What it does: 1 tool · 1 read, 0 write · Finance
No tool could be tested safely. Only read-only tools that need no input are called.
How the rating is made
- Answers without login: +30
- Speed of first answer: +6
- Lists tools: +10
- Tool descriptions: +15
- Parameter descriptions: +10
- Read/write annotations: +5
- Safe test call: +8
- More than 80 tools: 0
Tested 2026-10-17. Fixed rules, no AI model. Grade A needs a successful real call.
Install
Remote URL
https://check-digit.gumballtools.com/api/mcpTools
1 tools listed at last check
runValidate the check digit(s) on an IBAN, ISBN-10, ISBN-13, EAN-13, UPC-A, or Luhn-checked card number, and when it fails, try to say which digit is wrong. Use this instead of computing the checksum yourself. Mod-97 arithmetic on a rearranged 15-34 character IBAN, or a weighted sum mod 10/11 over 10-
Badge
Markdown for your README
[](https://clawy.uk/mcp/s/com.gumballtools/check-digit)