Consumers must be able to check the authenticity of the provenance, to confirm it was not altered after the build and to identify the build platform and other parties they must trust. This should be done with a digital signature from a private key available only to the platform component that produced the provenance, preferably with methods that make key compromise detectable (transparency logs, or time stamping where transparency is unsuitable). Accuracy: the provenance must be generated by the control plane inside the trust boundary it names, not by a tenant; its data must come from the platform itself; the platform must have some control stopping tenants tampering with it (no minimum strength). Tenants may supply only the output names and digests (subject) and fields not required at L2 (for example resolvedDependencies), and builders should document such fields. Completeness: should be complete, although some external parameters may be missing and resolved dependencies are best effort.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.