Many cocktail recipes are somewhat subjective, and so there can be a lot of variations from one "correct" recipe to another. However there are aspects of this recipe that I need to point out as being incorrect, even without looking strictly at the proportions of ingredients.
1. "Shot" of Tequila? And exactly how big is a "shot"? 1 oz? 1 1/2 oz? More? Fine to use "Shot" if all of the other measures are in shots as well, in which case it can be used as simply a generic ratio-based measure. But to then include "specific" measures such as teaspoon and tablespoon it makes this recipe difficult to determine exactly what was intended. If a "Shot" is suppoed to be 1 oz here, then just say 1 oz.
2. And if by "shot" you are intending somebody to use a "shot glass" for the measure, then saying "2 1/2" shots is also inappropriate. Shot glasses traditionally have sloping sides, and don't have "half" shot marks on them (although some do), so trying to measure a 1/2 shot pour is problematic.
3. Powdered sugar should be avoided as an ingredient in making cocktails. It includes cornstarch, which can get gummy, if not lumpy, when mixed with water. If what you are trying to do here is add a sweetener, and are thinking that such a fine powder will dissolve better, then you should use "bar sugar" or "extra fine sugar". Or better yet, use simple syrup.
4. Blender? Please no. A "real" margarita is not a "Slushee" (tm). Let's teach people how to make drinks properly first, and then we can introduce them to some of the "variations". Sort of like posting a recipe for Tiramisu using twinkees.
5. And why are we listing a recipe for "2", when technically it is a lot easier for somebody to "double" a recipe for "1", instead of "halfing" a recipe. If they aren't good enough at math to double a recipe, then then can easily simply go through the ingredients twice.
The one (very) good thing I can say about this recipe, is that it doesn't call for "sour mix". Thank You! :->
(Hmm... the system lost all of my line-breaks in that last post for some reason)