Well, yes and no and it is a matter of taste and where the url resides on the Profile.
Say you had someone who was a farrier by trade and you wanted to note this in his Bio. Darn few people know what that means and you wanted to link to the Mariam-Webster site for the definition:
John Smith was a farrier by trade. https://www.merriam-webster.com/dictionary/farrier
Well, that looks a little tacky so you want to use the brackets here.
John Smith was a [https://www.merriam-webster.com/dictionary/farrier farrier] by trade. Will look like this: John Smith was a farrier by trade.
But when embedded in a reference notation <ref> </ref>, some folks like myself, prefer to see the url so I know where I am going when I click it. So you can have a naked url, as it is some times called, in there. Some folks think that is still tacky as well and use the example I showed in the earlier post.
So in the written Biography section the brackets should be used with the written description. If in a reference as a source url, it is really a personal option. But if you use it there, add the description to make it easier on your viewer.
And about links to paid sites, if that is all you have, then use it. I chuckle as many times the folks who complain the most usually have a Profile that references a book that is not available online and I have no way to get a copy of it because it has been out of print for over a hundred years. Yet that reference I can't readily verify is perfectly OK to them. It's 6 of one and a half dozen of another. LOL
Happy formatting Tina.
Oh and here is someone in my tree Roy Schrengost/Schreckengost