Common here is All yours. But I'm not sure whether or not it's practiced internationally. Which one is better? Or all are okay? Any grammatical error?
I am strictly talking about the scenario wherein using these phrases should only mean that the possessor is allowed to do anything to what is given to them. Kindly do not come up with other cases where the possibilities of using these phrases increases or brings perplexity.
One of the scenarios:
"Listen, the sales are down and in coming days, the situation will go from bad to worse. And I don't want this to happen to our company. It is for this reason, I'm appointing you as the manager of this region. You need to work harder for this."
"Okay. But then I need some structural changes. Also, the way field workers work here is not a professional way. And…"
"Ah, whatever. You are free to do anything. It's all yours."
Note: Instead of uttering the last sentence, I may do some gesture spreading my arms and say, "All yours." to avoid "It's."
Further interesting is if I am talking about some workers (say field guys) here.
"I know the issue of field workers. In interest of the company, you can treat them the way you want. They are all yours/They are yours/All they are yours/Everybody is yours"
Best Answer
The expression that sounds better to me to express decision-making in this context would be:
Because that way you are telling someone you want him/her to decide about something, which would be the same as: "The decision is yours". For me this is the big difference compared with the "* all yours" expressions which don't necessary imply decision making.
Usually "(*) All yours" is used to express the availability of someone or something in an informal way:
Or to tell that something now belongs to someone:
In your last example, it seems right to use "They're all yours" (at least for me, the other options don't sound natural) because the workers could be treated "as someone wants", that could be interpreted as them losing some of their rights as humans and "taking them as objects". I've found a similar use in this book, but with girls instead of workers.
Extra (related with some previous comments on the question): "It's all in your hands" is more like "it's down to you". These expressions are used when for some reason you're the only one who could take that task at that moment. See this