Being perceived as having a high level of integrity and thus building trust is not difficult.  Believing that you need to commit to actions and then complete those actions is the simple personal value that covers this.

Accepting responsibility for something requires communicating what you plan to do.  This does not mean committing to the outcome (which sometimes is out of your control) but rather committing to an activity, something fully in your control.

Passive/ Aggressive

Being agreeable or apparently accepting of a change, task or directive with no intention of undertaking the action, or even undermining it, is classic passive-aggressive behavior.

This approach could be described as “say what you do but don’t do what you say”.  This method won’t inspire trust but then it is not intended to.

To sabotage an unwanted change or objective is the goal and this technique is easier than being candid or blunt about how you feel.  It is certainly a way to avoid confrontation but does include significant reputational risk.

Not Locked In

A common concern I hear about the straightforward approach to “a promise is a promise”  it does not allow flexibility if things change and you are unable to fulfill the promise.

I beg to disagree.  The promise lays a foundation for expectation.  Ongoing discussion and communication resulting from changing circumstances are a reasonable and widely accepted way to keep expectations realistic.

Most people recognize expectations around an initial commitment can change as a result of circumstance.

Wording to this effect is often embedded in contracts and agreements where opt out of risk event clauses are inserted to ensure delivery on a promise does not become an impossible task.