Sure, so your application to the MGA will include two "Statements of Intent". One of which is: "400-500 words that identifies a global affairs question, topic or problem" and reflect how it is or could be addressed.
Because I read environmental science, I chose to do mine on climate change and water security, explaining how shared water resources are currently being managed by market forces, treaties etc. 400-500 words is approximately the same size as a report abstract. So essentially I wrote an abstract on the issue but unlike a normal abstract, I also cited key literature (because obviously there is no report to follow). Citing correctly and being able to summarise a topic into an abstract are key skills in academic writing style, so showcase that you have them.
I will expand on what I mean by, "read for a degree". At my university, at least at undergrad, we are always reminded that we 'read' our subject (i.e. "I read 'X'"). This is a polite way saying "remember your place" or "don't get carried away" because at the end of the day, this is your first degree and all your professors and every paper you read are much more knowledgeable than you. At least in the traditional sense, undergrad isn't the place for creating your own theories, instead, your aim should be to thoroughly understand the topic or literally 'read' as much as you can. This is why citing peer-reviewed literature in your reports in so important.
Good Luck!