Some people get labeled "difficult" for disagreeing at all. Others disagree constantly and are seen as sharp, valuable voices in the room. The difference usually isn't how often they disagree. It's what they're actually optimizing for when they do.
Productive disagreement is aimed at getting to the best outcome, even if that means you end up agreeing with the other side by the end of the conversation. Difficult disagreement is aimed, consciously or not, at winning, at being the one who was right, at not backing down, at making sure your position is the one that's recorded as correct. The words used in both cases can look nearly identical. The intent underneath them is what people actually sense, and react to.
One honest test: after you've made your case and heard the other side's reasoning, are you actually able to change your mind? If new information genuinely shifts your position and you say so, that's a strong signal you were arguing in good faith. If no amount of counter-evidence moves you, and the conversation just keeps circling back to your original point restated a different way, that's usually a sign you've stopped disagreeing productively and started just defending a position.
"I think we should hold off on this launch, here's my concern about the data. [Hears counter-argument.] That's a fair point I hadn't fully considered, if the rollback plan is as fast as you're describing, that changes my read on the risk. I'm still slightly cautious, but I'll support moving forward."
That example shows disagreement doing its job: surfacing a real concern, genuinely engaging with the response, and landing somewhere honest, even if it's not full agreement. Compare that to someone who raises the same concern and, regardless of the answer, keeps restating it in slightly different words until the meeting ends. The first version gets invited back into the next hard conversation. The second version starts getting worked around.
How often you disagree matters less than people assume, but it's not irrelevant, someone who disagrees with literally everything starts to read as reflexively contrarian rather than genuinely discerning, which eventually gets discounted the same way a person who agrees with everything does. The goal isn't a target number of disagreements. It's making sure that when you do disagree, it's because you actually see something worth raising, not because disagreeing has quietly become part of your identity in the room.
Last piece: once a decision is made, even one you argued against, support it visibly rather than continuing to signal reluctance. Disagreeing well includes committing well afterward, that combination, argue hard then commit fully, is what actually separates a valuable dissenting voice from someone the team starts to see as difficult.