If you have lists of strings, it might be fastest to do one of these:
   expr {[lrange $list1 0 end] eq [lrange $list2 0 end]}
(and you can optimize that quite a lot if one list is relatively static,
which is often the case.)

Otherwise you have to do an element-wise comparison. For example, here's
a basic comparator for numeric lists (ignoring float-comparison issues):
   proc numlisteq {list1 list2} {
      # Do this check first; it's fast!
      if {[llength $list1] != [llength $list2]} {
         return 0
      }
      foreach i1 $list1 i2 $list2 {
         if {$i1 != $i2} {return 0}
      }
      return 1
   }

For general numeric values, that's probably optimal. (And no, this isn't
simple to solve in other languages either. Well, not unless you're lucky
enough to be able to use someone else's pre-built solution.)