How reobfuscate mod (forge 10.12.0.985)? Files in the bin folder does not work "[Client thread/WARN]: Zip file PG.jar failed to read properly, it will be ignored"
That should work
public static Item mysimpletool;
mysimpletool = new ItemMySimpleTool().setUnlocalizedName("mysimpletool").setTextureName("yourmodid:mysimpletool");
GameRegistry.registerItem(mysimpletool, "mysimpletool");