I have a spell: Telekinetic Field and I've had trouble simply conveying what the spell does.

My example: A adult red dragon exhales their fire breath, a wizard casts Telekinetic Field. The wizard fails their saving throw and take 31 points of fire damage (As the average damage is 63 points). A goblin runs up to the wizard and fails their saving throw and also takes 31 points of fire damage, incinerating. If the wizard had succeed their save and the goblin did not, the goblin would still have taken 31 points of fire damage.

How do I make this clear? Advice on power level, duration, and the like are also appreciated. 

1 round duration sounds about right. 

I'd suggest looking at the Great Old One's Thought Shield; the absorb elements spell; and the Evasion feature shared by rogues, monks, and certain Hunter rangers. 

I would also like to suggest, as strongly as possible, that you should rewrite the first sentence.  I might, in doing so, quote a certain fictional Spanish swashbuckler whose name I have no idea how to spell. 

I must echo Matthias: the first sentence is going to have people thinking of a table loaded with food, not a strong wind.  I realized immediately you were using the verb, not the noun, but I still had this very...odd...image in my head of a wizard warding the area with a all-you-can-eat table. :D  I suggest "redirect."

The reading of your spell suggests to me that in the example you provided the goblin should have taken half of the half, yes?  The wizard took half damage (31) because of the failed save.  If the goblin fails the save the spell description says it takes half the damage you sustained, which is half of 31, not also 31.  In the second example, the wizard sustained no damage at all, so on a failed save the goblin would have taken half of zero.  Did you mean that the goblin is subjected to the full strength of the triggering attack?  If you *did* mean that, I think it might be a bit to strong.  Here is my reasoning: If the goblin was already adjacent, it could already have been a target of the AoE.  This spell could theoretically make it save for the AoE twice, if it  moves at all before the spell's effect is over, because your wording says "moves within 5 feet."  I suggest "approaches within 5 feet."

Also the first part of the last sentence: at which point in the wizard's turn does the effect end?  Specify the end or the start.  I assume you mean the start, but it could be interpreted either way as it is currently worded.

It's been republished with some revised wording and revised level. Is it better?

As written, I can cast this in response to being in the area of a sleep spell.  It won't do anything, but I can cast it. 

It is better, though. 

Definetly better.