It’s expected that installation operations like memsql-deploy install requires root/sudo in a regular Tools installation. However operations like memsql-admin list-nodes and memsql-admin restart-node should not require root/sudo normally. It’s possible that they do in your case because of permissions issues, since you registered an existing cluster that may have been installed under a different user, or something like that.
You can install Tools without root/sudo, see this answer: