Vocabulary
Each is defined here once and used the same way everywhere else on this site.
A design system is correct by design when the wrong build is impossible, not discouraged. The constraint lives in the code: the component API, the type system, the token pipeline, the build. Nothing depends on anyone reading a guideline. The term names a property of the system, not a quality of the design.
The gap between what the system defines and what the application actually contains. A hardcoded colour, a one-off button, an inline style that reproduces a token by hand. Drift is not a record of debt. It's a prediction, because an agent reading the codebase can't tell precedent from regret and treats whatever is there as how things are done.
Advice is a rule a builder can take or leave: a guideline, a lint warning, a page in a docs site. Law is a rule the code enforces, so breaking it fails the build. A design system made of advice holds by convention and goodwill. A design system made of law holds by construction. Most systems are advice with a few laws in them, and the assessment measures which.
Something is true by construction when the way it's built makes the alternative impossible, rather than checked for afterwards. A Button whose type accepts exactly three variants can't produce a fourth. Documentation generated from the code can't drift from it. By construction is the strongest form of enforcement and the first of the six properties is its measure.
What the assessment reports when it can't see something, with the reason attached. It is never rendered as a failure. A repository the instrument can't read is a limit of the instrument, and saying so is the difference between a measurement and an accusation.