Completeness asks whether the product does everything the specified functions require. A measure compares the functions present and working with the functions specified. The population is the functional requirement baseline, and the trap is that the baseline moves. A completeness result is only as good as the set of functions it was measured against, and that set has to be identified and versioned before testing starts. The draft places this family under functional suitability rather than under requirements management because completeness is a property of the product, not of the document. A requirement that was never written is outside the measure, and a requirement that was written and then dropped is a change to the population that has to be recorded.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.