Games : How do the covert ops mechanic work in Beyond Earth?

I've found a few pages online that discuss how the Covert Ops mechanic in Civ:BE works, but none of them actually use any numbers. The game explains that some Covert Ops are "Easy", "Medium", and "Hard". It also explains that intrigue level plays into the chance along with the rank of the agent.

But how do the mechanics for Covert Ops actually work? What factors determine the chance of success and how much do they affect it? Actual numbers would be preferred. I'd love to know what the actual math involved is.