After searching a while for the first title I tried the second one (as the plural authors made me question my results).

Did you mean: "Difficult Conversations: How to Discuss What Matters Most" by Douglas Stone, Sheila Heen, et al.? and: "Thanks for the Feedback: The Science and Art of Receiving Feedback Well" by the same authors?

Not the original commenter. Difficult Conversations is a great book for understanding the dynamics of communications. It has a lot of overlap with the NVC book, but it's very poor in terms of giving actionable advice. The NVC book has the opposite problem: Great in terms of giving actionable advice, but poor in explaining the "why" behind the advice.

Radical Candor is a very common recommendation along these lines as well.

Willing to take a shot at a quick tldr?

a google search turns up some thorough summaries. I would best sum it up with “The most common error made in communication is incorrectly assuming that it has occurred”. Communication is a skill that I see mostly taken for granted once people have a functional level, but it goes deep. It’s tied up with your self awareness, blind spots, etc. and so debugging your speaking and listening skills is a lifelong thing. These books lay out all the layers of assumption, bias, and miscommunication that happen by default in most conversations, and how to recognize them and take charge of a conversation and fix them.