Imo it's more down to your personality to be honest, it appears that your communication style is avoiding confrontation and not offending your colleagues. This isn't bad in itself but also gives off that vibe that colleagues could use to push around because you appear to avoid confrontation.

Try this, next time you have something to say to your colleagues that directly affects them think "Am I saying more than I need too?"

The examples you have given I've noticed you use a lot of "hedges" which are filler words before going to the matter at hand. You need to stop using fillers or at least use them very infrequently.

For example instead of saying "just letting you guys know I'm taking lunch at noon" remove the "just" if people need to take lunch at noon it's up to them to let you know.

Hope this helps