I have a situation in which i want to say that a particular task i just completed was rather silly, a fool's errand, but i need to phrase it in such a way as it doesn't insult the management team that gave me the task --as they regard it, currently, as vital.
How about, "Barking up the wrong tree".
hopeful or romantic in a way that is not practical
The implication is that the task is noble, worthy, but unlikely to succeed. It praises the values behind the goal, even if the goal is unattainable (like Dulcinea).
Perhaps you could use the word trivial or superficial?
If you see no value in the task being done than perhaps it is more effective to come up with arguments...
You could simply call it a "Small Task", to denote the relative ease and trivial nature of the task without implying a pointlessness in the endeavor. This suggests it is also quick though, so be careful using it to describe a task that would take a longer time.