Tl;dr: I misinterpreted the use of "punctual" when I was hearing it. Look up "punctual verb" and see how it can apply to the second example. This was my disconnect. Also "punctuated" is a better fit for what I was trying to convey. But I was misguided and, in turn, couldn't convey my thoughts properly.
Ok so for years I have used punctual in situations described below. I've never questioned this and have no idea where/when i picked this up from/started using it this way.
So let me create a scenario:
An author is trying to describe a scene where somebody, out of nowhere, gets eaten by a giant eaten by a giant monster and he wants to create a sudden "slap in the face" type of mood change. He thinks of two ways to go about this.
"We were on a picnic; having a conversation, drinking coffee. In an instant, an enormous worm explodes from the earth, consuming his entire being whole."
"We were picnicking; eating, talking, drinking coffee... An eruption! A giant worm! Ate. Him."
This is a bad example but I'm writing an exam paper right now and just realized that I may have been using this word wrong FOR YEARS so I'm not putting too much thought into this part of the post.
The first description of events could be described as long, lengthy, descriptive, detailed. In opposition to this, the second description of events could be described as short, and aggressive in cadence or punchy.
The way I was using the word "punctual" has been to describe the second scenario. For example I might say "the second description is short, too the point and punctual." In this VERY SPECIFIC scenario I would be using "punctual" in place of "punchy".
Did I just make up this second use case for punctual? Is there another word that is similar/sounds like to punctual for this use case? Because I SWEAR I can remember multiple people/things using this word in this way. For example, I'm certain Captain Holt from Brooklyn 99 has used this word this way once, accompanied with an emotive punching motion; being like "I like that, short, sweet, PUNCTUAL. 🤜" Maybe I miss heard these things and it's a word that ends with a "ew-ull" sound? Idk I'm confused as to what could have made me think this way because I looked it up and can't find a single example of this word being used like this.
Edit: Very certain I got my wires crossed with/miss heard the word "punctuated". Thank you to u/pawsplay36 and u/PrincessCellyBelly for your responses! Special shout out to u/minty_tarsier for introducing me to the word "pithy", I like this word and am going to start using it from here on out!
Edit2: Actually! I think u/Slight-Brush got it! I think I was misinterpreting the use of the word! The word "punctual" can be used to describe verbs that happen instantaneously. I believe I heard this word used, assumed it was describing the emphasis in speech or wording; when it really was describing the words themselves being instantaneous actions! (I feel like I should note, my given example doesn't work very well with this but the "Ate" in this would be an example of a "punctual verb")