I am basically a noob when it comes to D&D, but I have taken up the reins for DMing the 5e starter set. The group I am playing with is a mish-mash of some very new to D&D and some who lightly played years ago, and the "seasoned" players wanted to build their own characters, which I am totally down for.
One of the players rolled out a gnome rogue (strange but surprisingly effective build it turns out) and as a gnome he gets the Minor Illusion cantrip.
He was up against a big bad monk, the rogue with 1hp to his name, so used Minor Illusion to create a loud yell just on the other side of his foe. He wanted to distract the enemy monk so he could hide. The monk failed the save so I ruled that the rogue could have advantage on his hide check. He felt like his reward should be something better, but as DM I made a decision and kept the game chugging along, promising to check into the matter more later.
I can't find anything in the Player's Handbook that addresses the question to my satisfaction, other than the DM basically decides. Which brings me to my question: Is there anything in there to support my players plea of "more"?