What do the action point symbols mean next to combat skills?

[Loathian]

what does three empty circles mean next to a combat skill?
What about three solid white circles?
What about one solid white circle and two empty circles?

is there a legend somewhere explaining the icons?

[PlutonArioch]

Three empty circles - free action (does not cost ap)
Three solid circles - needs 3 action points (cant move and do this action)
One solid and two empty - needs one ap
One solid and three semicircles - repeating action (will repeat once per ap you have left)
And I think there is another:
One filled blue circle and two empty blues - leaves one ap after the action

[Seltin]

Is there a tutorial in game for this? I had the same question as well

[hottt3]

https://steamcommunity.com/sharedfiles/filedetails/?id=2998578500
A good mod for this.

[Telos]

I think there's also a symbol (probably added to the game since that guide was created) for actions like unicorn/banshee phase that require three action points to use, but leave you with one point to do something afterwards, somehow involving all three circles being filled/shaded.