David has already given you the correct answer to whether your statement is idiomatic.
But there is no straight forward answer to the question "Is this friendly?"
A question such as "What are you doing?" can surely be asked in a friendly manner; it can also be asked with a stern face and an ungracious behavior. It depends on the mood of the person asking the question and how much they care about your feelings.
Here are a few other ways that I have seen people do this.
- Hey guys, so what are we doing today? To this, the members will one by one describe their plan or duty for the day (See that use of "we"? Often a great leader will put that in instead of "you").
- Folks, something urgent has come up, and I need someone to take care of this. Who is the least busy today?
- Gentlemen, this is priority level 1. This needs to be done within the next hour. Now, which one of you can lend me a hand?
- Sometimes supervisors ask "How are things going guys?" And they expect you to tell them about what you are doing right now/that day.
The manner or tone in which this or a related question is asked depends on the culture of the organization, the personality of the manager/supervisor/employee, the manager's relationship with the employees, office atmosphere, weather, etc.