Review tolerance- and GD&T-aware code and logic — linear/angular tolerance, flatness, parallelism, perpendicularity, position, runout, datum references, tolerance stack-up, and measurement uncertainty. Use whenever code interprets dimensional tolerances, evaluates geometric tolerances against measured/CAD geometry, computes stack-ups, or reasons about datums and measurement error. Use this skill for GD&T questions, tolerance stack-up work, flatness/position/runout checks, or any "is this within tolerance" question.
