When asking someone to do something, it's tempting to say, "this should be easy," if you want it to be done quickly. The implication being that since it's easy, it shouldn't take very long. But, this can quickly complicate team dynamics if you misjudge how hard your request is.
By calling something "easy," the person you've asked for help can only hope to meet your expectations - anything short of that will let you down. Understandably, this is an unenviable position. So, instead of asking someone to do something "easy," consider asking whether your time estimate seems reasonable; this way you're giving people an opportunity to tell you if the timeline you've proposed is unrealistic. This chance for renegotiation prevents these interactions from feeling adversarial and makes it clear that you're on the same team, trying to accomplish the same goals.