msfb doesn't include P&R tools; icfb includes most of Cadence tools.
You may find more information in openbook.
System Administration -> Configuration Guide -> Design Framework II Configuration
there are 'icms' & 'icde', 'icca' etc. so check 'openbook'.
for i know, use icfb with layout edit ...; use icds with schematic entry & logic simulation.
icfb can start the most toools of ic package.