There is a IEEE (not Synopsys) standard for UPF
IEEE 1801™ Standard for Design and Verification of Low-Power Integrated Circuits, the Unified Power Format (UPF)
So, different tools of different vendors may support it. For example, from Synopsys, it can be read by VCS (with MVSIM), MVRC, DesignCompiler, IC Compiler, Formlity, PrimeTime, PrimeRail.
Usually, the designer manually creates initial UPF for the design, than it can be read by DesignCompiler and after synthesis, the DC can write out the updated UPF. ICC can also write UPF. Still, initial UPF should be written manually (as well as RTL). Maybe there are some utilities, that can help you in creating initial UPF (as, I hope, there are such tools for helping in RTL coding).