I have gotten this feedback from my managers couple of times. Problem is - in the past (in some other companies), I have been on the receiving end of negativity. Often times, being reprimanded for asking a question, in some of the other teams I was a part of. I recall that I was shouted at in front of everyone because I was too tired during one of my on-calls and dozed off, missing an on-call call at 3:30 AM. I recall these events getting escalated to VP level. It impacted me deeply.
While it was hard, I moved on from such teams and now I try to be kind to all engineers, especially junior ones. I make sure that their onboarding journey is as fast as possible and they are granted help that is required. Extending it further, as a part of calls with other stakeholders as well, I often tend to be with a softer tone. It has been mentioned by my manager that - "You often come across as too kind. If you know that you're right, then why are you not speaking it with confidence."
How do I improve on this aspect ? Recently, I did this course on assertiveness but thinking if there are some other tips from your end.
While we're talking courses, I'm just going to throw my course on Effective Communication out there 😁
I really appreciate this question and am glad it's now part of the Taro ecosystem as it illustrates the other extreme of communication: Being too empathetic to the point where it's not clear what you stand for. This is an extremely important balance to strike as to me, one of the defining attributes of a strong senior engineer and tech lead is that they confidently and deeply believe in a certain set of principles while being understanding of other viewpoints.
Here's the tactics I use to project assertiveness when I have to:
I don't know your exact situation, but I can definitely recommend a wonderful book on this topic. It's called: "Radical Candor"! And it basically says, that people are whether too kind to provide a constructive and direct feedback or too harsh to demonstrate enough care...
So your manager probably wants you to learn how to be more direct and provide constructive feedback, but without becoming too harsh on people. And this book can help you to become a little bit better in this.
I would also recommend asking your manager for a mentor within the company who they think could be a great example of not being "too kind".