The Symbol
function may have an optional description:
var foo = Symbol("some description");
var someString = "some description";
var bar = Symbol(someString);
Using description
promotes easier debugging: when a symbol is logged the description is used:
var foo = Symbol("some description");
> console.log(foo);
// Symbol(some description)
It may facilitate identifying symbols when one is observed during debugging.
var foo = Symbol();
var foo = Symbol("some description");
var someString = "some description";
var bar = Symbol(someString);