This technical note addresses a problem of model evaluation in the framework of robust steady-state tracking in l(1) the setup. The upper bounds on measurement noise, exogenous disturbance and coprime factor perturbations in a discrete-time linear time-invariant SISO system are assumed to be unknown. For a given nominal model and a given tracking controller, three different model validation tests are considered and the complexity of computing upper bounds on the worst-case steady-state tracking error, consistent with these tests, is analysed.