Currently no validation is provided for generated document and actually the spec is not requesting for vendors to do that [1] but it would definitely be a key improvement for customers and users in general to know that the generated document is checked and appropriate action is taken in case content is not valid (e.g.: log WARN messages etc.).

Online Swagger Editor [2] was used to verify that non valid content was generated.

Also it should be evaluated whether to mention this behavior in community or product docs.

[1]
https://download.eclipse.org/microprofile/microprofile-open-api-1.1.2/microprofile-openapi-spec.html#_validation

[2]
https://editor.swagger.io/