webhook_target_schema_invalid
The target's argument schema uses a construct the shared validator (vocapable_contracts.toolschema) does not enforce, or renders over the per-target prompt budget. Refused at registration because bind time would refuse it identically - a stored schema is always a bindable one. The detail names the offending keyword or the measured size.
Problem shape
Every non-2xx response is an RFC 9457 application/problem+json body. The type URI below is stable and machine-matchable, so branch on the final path segment (the code) and treat the status as redundant confirmation. See the error-handling guide.
{
"type": "https://docs.vocapable.com/errors/webhook_target_schema_invalid",
"title": "…",
"status": 422,
"detail": "…",
"instance": "/v1/…"
}