Fault tolerance asks whether the product keeps operating when a component fails. A measure relates continued operation under injected or observed failure to the failure scenarios tested. The evidence has to be a failure, not a design. A redundant architecture is a claim until a component is stopped and the product keeps working. The scenarios should be the ones the product is designed for, and they should include the failure of a dependency as well as an internal component. The measure should record the effect on users, because a product that continues in a degraded mode may still fail the task.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.