Late night hot take: You should tell players why mechanics are included in your game. if you have a mechanic in there intended to help pace encounters write that in the mechanical instructions, it will help players know how to use it and make balancing internal systems easier.
I have so much fun writing the why segments of mechanical instructions in my longer games and writing about the ethical implications of small mechanical details. I also love writing sections that are about how to modify the game for different play styles, its the coolest.
I really get to write about my design process IN the game and it means that my players have the tools to engage with the ways the mechanics are supporting the theme and experience. If they're pulling a mechanical lever why, what does it represent? Knowing can be illuminating.
What does making this weapon a bigger die do? Does it change how it feels to wield it or does it just make the number go up. Write about percentages, guides for what players should choose if they want different feels OR themes in their game.