Schema should have a required property defined, being explicit about which properties have to be included with the schema when it is used as part of a request or response
OpenAPI Schema Required Error
Message: Schema MUST Have Required Property
Policies
Schema Required Properties
Marking required properties in your schema objects tells consumers and validators which fields must be present. This prevents incomplete data and makes API interactions predictable.
Data Validation
Data validation at the API boundary catches problems before they propagate. Type checking, format enforcement, required fields, and enum validation are the building blocks of data integrity.