Currently the review interface, at least for First Posts on Stack Overflow, looks like this:
There are several lines of text describing the meaning of the various buttons, but almost no guidelines about what sort of content each one applies to.
I request that that text also have a link to the review guidelines.
Background: The new user perspective
I don't think many people would oppose adding such a link, which leads me to believe it is absent due to a perceived lack of importance or urgency. So let me explain the necessity as I see it from my perspective as a new user.
I've been actively participating on SO for about a week now, and at some point my reputation crossed a threshold (500) and SO started prompting me to review posts. "Ok," I thought, "I don't know what this is or really want to do it, but I'll try to be a good citizen."
So I start reviewing. After skipping several, I tentatively approve my first post, adding a comment for improvement. I then tentatively approve a second and get hit with a rather accusatory failed audit message:
I'll spare you the particular misconceptions that led me to approve this post, but the key is I was missing the information the review guidelines provide, particularly regarding the meaning of the word "spam" on Stack Exchange.
It seems to me that most new users will follow a similar trajectory: be asked to review, reluctantly agree, then get smacked by a failed audit due to never having been told how to review. In a sense I was lucky because I got caught before I could do much damage, but it still felt unfair: I was simply following the (minimal) instructions I had been given as best I could.
Why put nearly every user through this inefficient and painful experience when it can be prevented by adding a simple link to instructions?
Why didn't I just google for it?
It didn't occur to me that the task was of a nature that required specific guidelines. I got the impression from the existing UI that I had already been told everything I needed to know, and should proceed immediately reviewing posts. These instructions appear right above an actual post that, presumably, needs review now, as it was (in most cases) written within the past few minutes, and that clock is visibly ticking. I of course already have significant experience reading and writing SO posts, so it's not like I considered myself completely lacking any relevant experience and recklessly dove in anyway.
The context says "make a decision now, on the basis of the information in front of you". So I did.
This has been asked before
There is already an existing question along these lines: Create detailed “How-to-review” meta posts and link to them from the Review queues? Given that, I was hesitant to ask again, but:
That question appears dormant. I can (and did) upvote it, but that's unlikely to make a difference. To my knowledge, I have no other way to draw attention to this ongoing problem than to ask again. (I thought I was told in chat that MSE does not have bounties (turns out I misunderstood), and I don't have much rep here anyway.)
That question was asked before the guidelines were written, so the request has changed from "please write and link guidelines" to just "please link the guidelines".
That question does not really paint a clear picture of what a new user experiences, absent such a link.