On CMOS Shop Talk:
From the perspective of writers and editors, URLs do their best work behind the scenes or just off the page, in a browser’s address bar. In that role—as an internet address that will take you to a specific page online—it doesn’t matter all that much what a URL looks like so long as it works.
Looks do matter, however, when you need to mention or cite a URL in the text or share it with someone. Most domain names are easy enough to deal with (think Amazon.com). It’s when URLs go beyond the home page that they tend to get messy.
But just because it’s been copied from an address bar and takes you to the right place doesn’t mean you’re stuck with it. Whenever you’re dealing with a URL that isn’t reasonably short and readable by humans, you should look for alternatives.