In this work, we study how the user's hand representation impacts the training of tool-based motor skills in immersive VR. We created a VR trainer for a tool-based task, and conducted a user study (N=26) to evaluate how the hand visualization can influence participants' learning performance. Two groups of participants were trained in the simulator under one of the two experimental conditions: presence/absence of their virtual hands' representation, while a control group received no training. The results show that while both training groups improve their performance compared to the control group, no significant impact of the hand visualization is observed.