I was/am hesitant to write anything negative because as a tattoo, this is not something that you can just alter or change and fix based on a critique. I also did not want to be responsible for you suddenly hating your tattoo.
Not having a wide range of experience with tattoos myself, I can only say that my opinion is based solely as a viewer of this particular art piece. So be warned, although I am not trying to be a "jerk" this is not a nice review.
With something like this, symmetry is of the most vital importance. Your artist should have been able to make each side (left, right, button top, as well as each diagonal) look exactly the same from any angle. He or she should have been able to incorporate that effect, even though the canvas itself (Your arm) is not a perfect and smooth surface. Many of the lines throughout this piece do not appear to follow each other, and some do not even appear to be straight (curving or movingly slightly). Even the circular aspects of this piece seem to have poor line work. Further, the line work doesn't stand out. I see varying levels of depth to the lines (Some being thicker, others being thinner), but they fail to make any meaningful impression on the overall tattoo.
Then we have the shading. Shading should work to draw attention to certain aspects first, and others aspects second. It created a very good sense of depth to anything, if it is applied correctly. This fails to do that in any regards. Nothing actually pops out at the watcher (the watcher only referring to myself in this case). Shading can make a 2D image appear to be 3D so to speak. Not that you were necessarily going for a 3D image, but shading correctly would have improved this tattoo 100% in my mind.
Opposite of shading we have white space. Often referred to as negative space. The use of "nothing" to enhance the feel of what is there. Although technically your artist did utilize white space. The way it was done was ineffective. White space is one of those things that no one notices when it's done correctly, but everyone notices when it is not done correctly.
In my mind, and this may sound harsh. The only thing that could redeem this as a tattoo, would be if it held sentimental value. Such as a design from a child, or whatever. To me, this looks like something someone would draw when they were bored in math class, and not as a serious tattoo. If you yourself drew this that is perfectly fine. But your artist should have been able to look at it and redraw it in a way that would work as a tattoo for the size and position that you requested.