Your MCP server's own schema is silently killing valid agent calls before your handler, your logs, or you ever see them - this service witnesses those rejections, tells you which constraints are tighter than your upstream's truth, and receipts the calling agent so it escalates instead of quietly answering a different question.
Capture is proven for the rejection classes exercised in the lab (enum, maxLength, required, type); the differ as built covers enum constraints (pattern / required / numeric-bound differ legs are designed, not yet probed); classifications require a differ report for the server - without one they default to INVALID-INPUT and are not VALID-INPUT-REJECTED findings.
Pricing: rejection receipt $0.01/query; differ scan $4.99/server up to 25 tools; Operator $9.99/operator/mo (10,000 records, 10 included differ scans/mo); Fleet $19.99/operator/mo (100,000 records, 30 included differ scans/mo). One free rejection receipt query per operator, ever.
Support: support@textforagents.com