The councilman descendant allows you to draw two cards and keep one when taking the card action even if you discard nonmatching action tiles.
How does this ability interact with the two roof tiles which reduce the cost of taking the card actions? The two roof tiles in particular let you 1. take the topmost card action while only discarding a single action tile or 2. let you purchase the topmost card for a single coin.
Does the councilman's ability let you still glance at the top two cards when those roof tiles are active? Or do you still only get to purchase the topmost card of the deck?
In this case, you'll have to decide if you want to use the roof bonus or if you use the special ability of the descendant. It's on purpose that not all descendant are perceived as similar strong as players shall be motivated to move along the river.