Adapting ITSs that promote the use of metacognitive strategies can sometimes lead to intense prompting, at least initially, to the point that there is a risk of it feeling counterproductive. In this paper, we examine the impact of different prompting strategies on self-reported agent-directed emotions in an ITS that scaffolds students' use of self-regulated learning (SRL) strategies, taking into account students' prior knowledge. Results indicate that more intense initial prompting can indeed lead to increased frustration, and sometimes boredom even toward pedagogical agents that are perceived as competent. When considering prior knowledge, results also show that this strategy induces a significantly different higher level of confusion in low prior knowledge students when compared to high prior knowledge students. This result is consistent with the fact that higher prior knowledge students tend to be better at self-regulating their learning, and it could also indicate that some low prior knowledge students may be on their path to a better understanding of the value of SRL.