Hi Jim. There seems to be only i fact in your letter. Personally, I would add a few words for:
Why read my submission. (genre, reading level, how fits in with your magazine)
What background (education and experiences) caused me to write it.
Consider that if someone actually reads your letter, they'll want to know something about you and/or the submission. Your statement is saying the obvious since they already have your submission.
Hope that helps.
Have a nice writing day.
You're not dead 'til you're dead and when you are you won't know it. So, keep on writing and having fun.