@Switch Blayde
Maybe it's because my memory is so poor, but it's keeping things straight throughout. Character names, descriptions, relationships, etc. And then there are plot errors I make in later chapters that hopefully I catch when I re-read the draft. With a short story, that's not an issue for me.
I too have similar memory issues, due to multiple TBIs. I have learned to create a "bible" a document with the names of All of the characters as well as important locations, vehicles, aircraft, etc.
I also have a Timeline that may be a separate document.
Main Characters often have multiple paragraphs describing them, their appearance, education, military service, and any relevant family. Firearms, vehicles, or special skills, phobias, quirks, etc.
Reoccurring Secondary Characters get a paragraph.
Then there's
SSG Dixon the Regimental Clerk
Bob the Barber
Mrs. Davis the nosy neighbor
Captain Lewis the pilot
Mostly so I keep those names consistent, although I might have a brief description such as 50's bald, obnoxious.
Little of my descriptions goes directly into the story. It does keep Characters consistent.
For example: I have an 8 person medical team covertly parachute into Northern Mexico. All the members are fluent in Spanish. Several were born in Mexico, or lived there, or grew up in Mexican immigrant communities in the USA, and speak like native Mexicans. 1, a Doctor, is Cuban, but since a significant number of Mexican doctors go to medical school in Cuba, and some Cubans emigrate to Mexico, that is no problem. 1 other soldier, is fluent in Spanish, but speaks with an obvious USA accent, must keep quiet or just one word or very short answers.
Other times I just need to know which, if any Characters can drive a standard transmission truck. Or whatever, for story purposes.