Clustertool is a "run an operation against the whole cluster" tool, as opposed to nodetool which is single-node.
Clustertool never achieved feature parity with nodetool and never will for long, since it has to be manually updated for each operation type.
Since it's trivial to just use standard tools to run nodetool against an entire cluster, let's drop clustertool in favor of encouraging that.
Some examples. The first two assume a file "clustermembers" with your cluster host names; dsh will want that in /etc/dsh/groups instead of cwd.