For the tools to work effectively, you must provide as much information about the I/O characteristics and topologies as possible. You must specify the electrical characteristics, including the I/O standard, drive, slew, and direction of the I/O.
You must also take into account all other relevant information, including connectivity, clock topology, and timing constraints. Clocking choices in particular can have a significant influence on pinout selection and vice versa.
For IP that have I/O requirements, such as transceivers, PCIe® cores, memory interfaces, and high-speed I/O interfaces, you must configure the IP before completing I/O pin assignment. Refer to this link in the Vivado Design Suite User Guide: I/O and Clock Planning (UG899). It provides more information on specifying the electrical characteristics for an I/O.