In the child board "Story analysis", many short stories from picture books for kindie and year 1 have been used to illustrate that a short story can be really short and still has good quality with a full narrative structure. If students can write 200 words really well, they would already do well in a writing test. However, they can add a couple of more complications and extend to 350-450 words to meet the standard for a high mark in selective or scholarship writing jobs.
It is all about creative use of words, correct narrative structure, correct grammar and logical flow of events in the plot.
Students (and parents) should go through these short stories to see how stories should be written with SHOW strategy (and NOT TELL). They should be just descriptions and let readers figure out what actually happens.