cbor doesn't prescribe sending schema, in fact there is no schema, like json.
i just switched from protobuf to cbor because i needed better streaming support and find use it quite delightful. losing protobuf schema hurts a bit, but the amount of boilerplate code is actually less than what i had before with nanopb (embedded context). on top of it, i am saving approx. 20% in message size compared to protobuf bc i am using mostly arrays with fixed position parameters.