Cycle through Tools with Actuator

Use Custom Script action and "state" object form Actuator API to toggle group of tools with single button.
from krita import Krita
from actuator.api.utils import state

actions = [
i = state.get("tool index", 0)
action_name = actions[min(i, len(actions) - 1)]


i = (i + 1) % len(actions)
state["tool index"] = i

Download sequence.

Is cycling through tools is to much? Maybe you need just toggle between brushes. That is possible too.