What are the effects of my Agents getting "detected" in Beyond Earth

I've been reading over this excellent explanation of how Covert Ops work in Beyond Earth.

So far I've been working with a policy where, if one of my agents is "detected" whilst performing a covert mission and there is a counter agent in that city, I move that agent out of the city and replace him with another. This takes advantage of the raised Intrigue level for that city, but at the same time places another Spy in that city, a Spy that has not been detected, so they can continue performing missions without the increased risk of them having been detected.

But now that I've been reading how Covert Ops work, it seems the only historical factor involved in Covert Ops calculations seems to be the Intrigue level. In other words, the fact that my agents are "detected" appears to makes no difference to their future missions in that city.

Is this correct? Is the "detected" notice you get once a mission is completed relevant to the game at all?

If being "detected" does have an impact on future missions, can somebody explain how, and if my original tactics are sound.

If being "detected" does not have an impact on future missions, what is its purpose? Why does the game go to such lengths to say "Your agent was detected / undetected" when this detection has no bearing on the game mechanics themselves.