Minecraft wiki entry for Creating_a_data_pack, associated text: Once you have created your pack.mcmeta, try testing it out in-game! Open the world or, if you are already in the world, type /reload, then type /datapack list. It should list two entries. One should be [vanilla] (built-in), the second one should be named like [file/(your data pack's name) (world)], where your data pack's folder name goes at (your data pack's name). When you hover over your data pack's entry, you should see the description of your data pack as you have written in  description of your pack.mcmeta.