Agents of SHIELD is not only happening concurrently with the MCU timeline, it also ties in (loosely) with the films. Most notably with CA:TWS, which happened during the end of AOS season one, destroying SHIELD and totally upending the show's structure.
The tv and film universes aren't tightly tied together because there's been major executive strife between the divisions. It's too much to go into here, but Feige has broken away from the tv/comics side of the biz and gained control of the film empire. We'll not be seeing the tv characters in the MCU anytime soon, thankfully.