For me, set_multicycle_path is used with below condition:
- Timing violation on a path.
- Functional verification prove that, there is more than 1 cycle for capture FF to use the signal propagated from launch FF, on that path.
Hence, you need to ask Logic designer to provide set_multicycle_path.
If you dont have it, just start doing without set_multicycle_path, then collect the violated paths and review them. Pass them to designers for their comment on multicycle possibility.
Hope this helps.