Research on the use of learning tools has brought to light variables that influence the learner on using or not using the tools. A deeper analysis on the current findings is attempted in this study. It adds a psychomotor task; it assesses the actual functionality of the employed tools, and it further explores learner-related variables that influence tool use, most importantly on perceived tool functionality (the beliefs of learners that a certain tool would be the most optimal one). Fifty-eight learners had to build a LEGO® figure. Two tools were used: a video with intentionally low functionality demonstrating the figure assembly, and a step-by-step guideline with pictures. Based on the tools, there were three experimental conditions: guideline (G), video (V) both tools (GV); and one control condition (C) without tools. To analyze the functionality of the tools, the effect of tool use on performance was monitored at two different moments in all conditions. To examine the perceived functionality of tools, the tool use by the learners was monitored in the (GV) condition. Moreover, we checked for the effect of prior knowledge, metacognition and self-efficacy on tool use in the (GV)condition. Results revealed that the tools were functional. The (G), (V) and (GV) conditions significantly outperformed the (C) condition, but contrary to our assumptions, the (V) condition outperformed the other experimental conditions. Regarding perceived functionality, all learners perceived the tools as functional, that means all learners picked a tool. They, however, could not identify from which tool they would benefit the most, i.e. they could not recognize the most functional tool. Concerning the other learner-related variables, no significant effect was found. Theoretical implications for further research are discussed. First on what kind of tool-related variables influence tool use. Second on the effect learner-related variables, especially perceptions, might have on using tools.