Yes, I can. And the description of half-plate is not a rule. Just like I am violating no rules by having bone hooks in the fishing tackle. You claim it is a rule. And you have no evidence.
Really? Because if these are supposed to be rules, not just descriptions, then the only armor that includes a helmet is full plate. No other armor comes with a helmet. That is a rule, so I'd be breaking it and wearing something else if I was not in full plate but had a helmet.
Plate and Scale mail are the only armors that come with gauntlets, if I describe my character as wearing gauntlets, but I am not wearing one of those armors, I'm breaking the rules, right? Because that is a rule.
what if I want to wear breastplate, but I also put on magic bracers? Breastplates "rules" say that they have to leave the legs and arms unprotected. And those bracers clearly have a mechanical impact beyond just being cosmetic. Am I allowed to wear them with Breastplate? What about with Full Plate, if I replace the gauntlets required by the "rules" with bracers and gloves of missile snaring, am I breaking the rules by taking away part of the armor for a mechanical benefit?
Or do the descriptions of the armors only count as rules in the singular instance that they can't be made out of different materials? What if I have leather armor that was boiled in water mixed with wood ash, am I breaking the rules? Because the "rule" is that leather armor is made out of leather boiled in oil.
Hide armor is made of furs and pelts, and a pelt is a hide with fur on it, so what if I said my hide armor was made out of a scaled creature? Does that break the rules, since it is made out of a different material? I mean, Hide isn't made out of skins, so I can't do that right?
Or, last question, are all these sort of ridiculous, because the description of the armor isn't a rule that has to be slavishly followed?
"The rest of the spell entry describes the spells effect" That is a rule that tells you that was is described in the spell is what the spell does. Hence, wall of fire creates a wall of fire, not a wall of water. Why can't a spell do more than what it states? Because the rules say that spells are a "specific, limited expression."
I'm showing you the rules, exactly like I said I would.
Do you think before Tasha's you weren't able to describe a spell differently? Because you seem to subscribe to a "only what is directly stated" reading of the rules.
You wanted examples of why a wall of fire can't be a wall of water. I personally think that the first lines from the PHB cover it. A spell does only what it says it does, and Wall of Fire states it creates a Wall of Fire, and spells are discrete, limited effects. However, Tasha's came out and allowed changes, so couldn't I change the spell? Well, they directly stated that you can't change the spell effect or make a spell look like another spell. Like say... Wall of Fire looking like Wall of Water. So, yet another reason that you can't cast Wall of Fire and create a Wall of Water.
IS there anything like that for armors? Anything that says you cannot make an armor out of anything not described in the armor description?
So, I would never be able to swap steel hooks for bone hooks in Fishing Tackle, because there is a rule that interacts with that description, so it would be homebrewing and the player cannot unilaterally decide to change the rules in that manner. Same with metal ball bearings, can't let those be glass beads, that changes a rules interaction. Same with a hunting trap, can't make a hunting trap that isn't a saw-toothed steel ring, that interacts with another rule, so those are the only types of hunting traps allowed. Mirrors can only be made out of steel, can't have any other type because that would change a rule interaction.
Or, maybe, just maybe, this is ridiculous. A bizarre standard that you are making up without really thinking through how utterly strange it would be.