"I wonder if they have tools or suite of tests "

YES! There is a a program for automatically checking for defects in any photographic image!
This program does an amazing array of automatic check points on any image:
1. It checks to make sure your image is properly framed.
2. Checks on contrast.
3. Checks color.
4. Checks for noise.
5. Determines if the image is aesthetically pleasing to the eye.
6. Determines if the image is properly focused.
7. Evaluates the image for saleability of any stock website.
8. Automatically spots jpg artifacts.
9. Determines and evaluates proper lighting. (blown highlights and shadows)
10. Evaluates the image for proper key wording and description.

A copy can be obtained here: http://unnaturalphotos.com/defect_checker.zip

I just can't help getting on board here and posting my comment.
Allow me to say this right from the beginning: Becoming a reviewer is a tedious, boring job.
Figure your worth per hour BEFORE you consider working as a reviewer. Is it $10.00, - $15.00, - Maybe $20.00 an hour?

After you have decided what your time is worth and hour, try to picture yourself on the same pay scale level as a 7-11 convenient store clerk.
Thats where a reviewers pay scale falls into. Your actual pay will vary from site to site, but it generally falls between 3- 5 cents an image.

If we break that down into an hourly basis this is my scenario:
1. Perfectly alone,  isolated with no one around to bother you, no disturbances.
In this case you can probably bang out about 5 images a minute...300 in 1 hour.
Remember, if you deny any images, you usually have to match up your denial with a "canned" response. Like "Too much noise"...."Not focused properly" etc.
300 X .05 = $15.00 an hour
300 X .03 = $9.00   an hour

2. Mild distractions, like going to the rest room, taking a break, stopping to eat, the phone rings....etc
Over an 8 hour period my guess is your average will drop down to about 3-4 images a minute.
180 X .05 = $9.00 an hour
180 X .03 = $5.40 an hour
----------------------------------------------------------------------

It's always been a concern of mine that SS takes it's reviewers strictly from their forum.
With limited knowledge about who they hire, and their particular skills, I have always thought
that SS reviewers were the worse in the industry.

On a more positive note, I see this as a perfect opportunity for any new photographer just coming into
the stock photography circle, to learn, learn, learn! You will see a vast number of images, and techniques
that will help you as a photographer. You can learn what pitfalls to avoid, and what works, and what does not.

Good luck to all applying for the job.

Photoshop Beginners/Intermediate Users
Pocket technique #6 - My sixth attempt at showing you how I open an image.
examine it, and decide then and now (depending on my mood) what I'll do with it.

Photoshop is my toy box full of goodies to play with. I love having fun and experimenting.
This is how I learned. Watching others do exactly what I'm about to show you.i

This is #6 in an entire series and all are quick and short things you can so in less than 3 minutes

http://microstockpix.com/tuts/pt6/pt6.html

I don't like it
It's too dark
Very little or no detail
Boats are too far away
It has an orange color cast I don't like
The horizon in smack in the middle of the frame

"Photoshop Kindergarten" Masking
One of the most powerful tools in Photoshop...period!
This is the first set in a series of "Photoshop Kindergarten"
Designed for the RAW beginner who owns photoshop but is too lazy to learn it.

First lessons are MASKS What are they? and What do they do?

http://microstockpix.com/tuts/masks1/masks1.html
http://microstockpix.com/tuts/masks2/masks2.html
http://microstockpix.com/tuts/masks3/masks3.html

(more to come)

Photoshop Beginners/Intermediate Users
An alternative method to the Unsharp filter.
This method has some advantages and there are 3 different blend modes you can use.

http://microstockpix.com/tuts/hps/hps.html

Photoshop Tutorial - For Beginners (easy)
So simple my dog Nicky can do this!


http://microstockpix.com/tuts/lc/lc.html

For Photoshop Newbies and Beginners - Learning Basics
WOW! Photoshop just made it easier to make fairly good selections
without all the fuss and muss of the magic wand.

In this introduction, Ill show you how to make use of this tool with some ease.
I'll only "begin" to touch here what this tool is capable of doing. I leave out a lot.
But I'll bet I show you enough to catch your attention and intrest in learning more.

http://microstockpix.com/tuts/qs/qs.html

Photoshop Beginners/Intermediate Users
Pocket technique #3 - My third attempt at showing you how I open an image.
examine it, and decide then and now (depending on my mood) what I'll do with it.

Photoshop is my toy box full of goodies to play with. I love having fun and experimenting.
This is how I learned; watching others do exactly what I'm about to show you.

This is #3 in an entire series and all are quick and short things you can so in less than 3 minutes

http://microstockpix.com/tuts/pt3/pt3.html

Photoshop Tutorial - For Beginners and Intermediates
Have you ever tried to male a selection with the magic wand, and the selection
either extends too far or includes parts of an image you didn't want. Well many
people know that making a selection, and then while holding down the shift key ADDS
to the selection.

I'm going to show you how to make a difficult selection by subtracting
from the selection.

Then I'll take it one step more and show you a peek at what "Replace Color" can do.
http://microstockpix.com/tuts/blue/blue.html

Photoshop Tutorial - For Beginners and Intermediates
Nope. It's never happened to me...no sir. I Always remember to set my
WB (white balance) correctly on my camera before I shoot. (I lie alot too)

So here we go. OK so this guy forgot (not me)....it's ok. We have another chance.
Let me show you how it's done. Correcting the WB

http://microstockpix.com/tuts/wb2/wb2.html

Photoshop Tutorial - For Beginners and Intermediates
Mostly found in my landscape images, Haze obscures, and detracts from the overall image quality.
Although there are several methods and techniques for dealing with theses images, the method I
prefer to use is this one. It give me good results, and I feel I have total control of what is happening
to the image.

http://microstockpix.com/tuts/haze/haze.html

Photoshop Tutorial - For Beginners and Intermediates
We all have them...images that just don't have what it takes .
All images should promise "If you look at me, I'll put you in a mood"
What mood? Well thats up to the image.

Here I take a otherwise junk image, and transform it into a "moody" image.
The technique is what I call a "pocket technique". Something I just put together
on the fly, either from another technique I saw someone else do, or one I just
create on the fly, as I go along.

This tutorial is for CS2 and CS3 users as it employs using Smart Objects.
I can do the same thing in CS too, and will have a tutorial soon for those users.

http://microstockpix.com/tuts/pt1/pt1.html