Results that point to animals' metacognitive capacity bear a heavy burden, given the potential for competing behavioral descriptions. In this article, formal models are used to evaluate the force of these descriptions. One example is that many existing studies have directly rewarded so-called uncertainty responses. Modeling confirms that this practice is an interpretative danger because it supports associative processes and encourages simpler interpretations. Another example is that existing studies raise the concern that animals avoid difficult stimuli not because of uncertainty monitored, but because of aversion given error-causing or reinforcement-lean stimuli. Modeling also justifies this concern and shows that this problem is not addressed by the common practice of comparing performance on chosen and forced trials. The models and related discussion have utility for metacognition researchers and theorists broadly, because they specify the experimental operations that will best indicate a metacognitive capacity in humans or animals by eliminating alternative behavioral accounts.