How long should this piece of writing be?
As long as it needs to be.
Sometimes, that’s going to be pretty long. But most of the time it’s going to be shorter than you think.
What’s it for? What’s it really for?
Playing with an idea for pages and pages can be fun.
Making a connection (which is really about getting a response) can and probably should be quite short.
And teeing up a decision requires adequately addressing the context while also being spare and clear enough that a choice can actually be made.
(That’s the standard three examples right there … were they the best I could have picked? Would you like to see another, or do you already get the joke?)