iOS Build a Simple iPhone App with Swift Getting Started with iOS Development Swift Recap Part 1

What is the correct way to pass a string to the Tag Object when creating a constant (in this case firstPost).

My current solution results in

"iOSDevelopment by Apple. Filed under Tag(name: "swift")"

Also I am sure there is a better way to create a Tag object while creating a Post object.

structs.swift
struct Tag {
    let name: String
}

struct Post {
    let title: String
    let author: String
    let tag: Tag

    func description() -> String {
        return "\(title) by \(author). Filed under \(tag)"
    }
}

let aTag = Tag(name: "swift")
let firstPost = Post(title: "iOSDevelopment", author: "Apple", tag: aTag)


let postDescription = firstPost.description()