Good MBA Essay goals:
are a logical progression of your experience and the MBA
The short-term goal should be relevant to both your experience and the MBA you'll get. At the same time, any mid-term or long-term goals should be well-thought out and connected to the achievement of the short-term goals.
show you at your best
What is your potential, given your current level of experience and the MBA to which you are applying? This should be seen through your goals. If you can and want to position yourself to be running a company that is changing the world, then this should be in your goals.
confirm your passion
What kind of impact are you really passionate about having on the world? Where does that passion come from? The answers to these questions should be apparent in a well-crafted goals essay.
are easy to explain/understand and therefore grasp
You don't want to have to spend 2 pages or 5 minutes detailing what your goals mean, or why they are important. Good goals should be clear and impressive.
This is perhaps the most important thing to remember. The goals you put in your application are not a promise, nor are they your father's wish or the instructions from your boss. They are instead a portrait of your potential, an advertisement of what you are positioning yourself to become, an introduction to who you are now and will be in the future that puts you in the best possible light and maximizes your chances of getting admitted to a top MBA program.