S.MISCAST.S₁ — Substrate–role mismatch

A person, tool, or artifact is carrying work it is badly suited to carry.

Your teenager's calculus grades are climbing, and it worries you. You watched him do homework last night: photograph the problem, let an app produce the solution, copy it down. The tool is excellent at solving. The trouble is that solving was the exercise. The reasoning he was supposed to build is being carried by software, and the strong grades are hiding the loss.

Substrate-role mismatch names this failure shape: a person, tool, artifact, or environment is carrying work it is badly suited to carry, or work that should not be transferred at all. The cue is a carrier straining, or performance that looks fine while the underlying capability quietly erodes. Run it with two questions from the spec. Which burden belongs on a different carrier? And which human act is itself part of the desired outcome, so moving it destroys the point? Here the answer is plain: the struggle is the product, so the solver must go, at least during practice. When the diagnosis works, you reassign the load instead of tuning the current arrangement. Skip this label when the carrier fits fine and the real issue is missing checks on its output; that is a control gap, not a mismatch.