descriptor

Describes the structure of the serializable representation of T, produced by this serializer. Knowing the structure of the descriptor is required to determine the shape of the serialized form (e.g. what elements are encoded as lists and what as primitives) along with its metadata such as alternative names.

The descriptor is used during serialization by encoders and decoders to introspect the type and metadata of T's elements being encoded or decoded, and to introspect the type, infer the schema or to compare against the predefined schema.