Api Gateway validation response don't include field names

Hi, I'm using request validation feature on the Rest Api Gateway and I would like each validation message to contain the name of the field that did not meet the model definition. Is it possible to achieve this on gateway side? I've configured 'Bad Request Body' -> 'Response templates' with following value: {"message": "$context.error.message", "validationString": "$context.error.validationErrorString"} And some of $context.error.validationErrorString values don't include a field name. For example i got response: "validationString": "[instance type (null) does not match any allowed primitive type (allowed: ["string"])]" And it isn't clear which filed has improper format.