Imagine a genie who offers to grant you your wishes. There is only one cavet: you can tell that the genie is incredibly flakey. You deduce that the genie very likely won't grant your wish if it would benefit or impede your goals too much. That's just the biggest factor in how difficult the magic is for the genie to perform, as he explained to you. That means that detonating a random star on the other side of the universe would be about the same difficulty as materializing a glass of water that you probably could have gotten yourself. But granting you insane reality warping powers or something is probably just going to result in the genie giving up and moving on.
Unfortunately you are not able to tell the exact cutoff for what kind of spell the genie is willing to perform, since the genie is too afraid of seeming lazy to give you an unbiased answer. You can ask for as many things as you want, but the genie will disappear forever after you finish asking. What would you wish for? Would you risk asking for a bigger wish?
