Updated tail description

snippets/tail-of-list.md

@@ -1,6 +1,6 @@
 ### Tail of list
 
-Return `arr.slice(1)`.
+Return `arr.slice(1)` if the array's `length` is more than `1`, otherwise return the whole array.
 
 ```js
 const tail = arr => arr.length > 1 ? arr.slice(1) : arr;