To me putting the link first is extremely counter-intuitive, as if writing plain text I'd also be more likely to write out a description of what I'm referencing first, and then enclosing the link in parentheses.
Thankfully with Markdown that makes it easier to remember - the URL part is as it always was, and I just need to mark which part of the text makes up the description.
> [The W3C recommends not using "here" or "click here" for links.](https://www.w3.org/QA/Tips/noClickHere)
According to the original vision of hypermedia, the text should be able to stand on its own and the hyperlinks are added on top of it. This keeps the link text semantic by itself without relying on the hyperlink.
And the entire point of Markdown is to get something that is closer to how we write plain text.
> link_to "Text", "http://example.com"
And Markdown:
> [Text](http://example.com)
It's pretty easy to remember the order after a while.
For example, [[www.example.com]] makes sense.. it will render as www.example.com that hyperlinks to that link. But [[link description]] is useless by itself.
So.. put the more important thing first, the link:
Now, if you also have a description text for that link, put that afterwards.. Hope that helps.