How many articles of each kind arrived in this version — items,
creatures, quests, spells and seventeen more — as one flat object of
counts rather than a listing or a record. Every kind is reported,
including the ones that are zero, so a caller charting content across
versions never has to read a missing key as nothing. The whole answer
costs one query however much the update shipped.

Every key here is a count, which is why each is spelled out: items and
creatures name a relation on every other endpoint, and the shared
dictionary of field meanings describes them as one.