Schema properties that are of the type array must have an items property defined
OpenAPI Schema Properties Array Items Info
Message: Schema Array Properties Has Items
Policies
Parameter Types
Getting parameter types right -- integers, strings, arrays, numbers -- with proper formats and constraints prevents a whole category of integration bugs before they happen.
Schema Property Shapes
Property shapes -- min and max lengths, array bounds, number ranges -- define the constraints on your data. These constraints are what prevent garbage data from flowing through your APIs.
Schema Property Type
Property types define what kind of data each field holds. Getting the types, formats, and array item definitions right is fundamental to an API that works predictably.