Don't justify everything you say with reasons
People sometimes communicate starting with reasons, and building up to the conclusion. This is little-endian communication. For example:
You know what's coarse, rough and gets everywhere? Sand. It damages your machinery.
The alternative—big-endian— starts with the conclusion and gives reasons afterward:
Sand damages your machinery. It's coarse, rough and it gets everywhere.
This is a better style of communication unless you’re a detective story writer or a comedian. Why? Because people are interested in the conclusion more than the justification. In maths class, we’re taught to build up a theorem step by step: A => B => C => D. But real life is not a maths class, and people want the conclusion first, so that they can act on it, such as by insulating the machinery from sand. Why sand damages machinery is secondary.
People tend to daydream and lose focus at the drop of a hat, or interrupt, and big-endian communication lets you communicate the most important part before that happens.
While big-endian communication is better than little-, even better is skipping the reasons:
Sand damages your machinery.
If someone asks, you can always explain.
Some of us explain preemptively because we feel inadequate and explain why as a defense mechanism. But that creates a social dynamic of putting yourself in a weaker position: weaker people are the ones who have to explain themselves to stronger people, not the other way around. So when you explain ahead of time, you’re perpetuating your weaker solution.
We sometimes explain unasked in order to preempt questions. But reasons can be an invitation for the other person to opine, perhaps because they’re nit-pickers. If you dismiss the question, people may think you’re being dismissive. If you engage, you may get into a second conversation, losing track of the main one. The best solution is not to give question-askers an opening in the form of a reason that wasn’t asked for in the first place.
Giving unnecessary information also bores people. They may miss the main point among the reasons, hanging up the call and not knowing what the point of it was.
UX design has a principle of progressive disclosure: only information necessary to the user is shown. Only if the user clicks a More button is more information shown. Implement progressive disclosure in your communication.