The registry is organized so that someone designing an application can find out whether a fitting description already exists; where a new one is truly needed it is derived from an existing description with the necessary changes, avoiding needless variants. Registration also exposes two items that describe the same object, and, more importantly, names that are the same or alike on items that differ materially.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.