Is PHB p55 considered declarative:
For instance, a power that deals acid damage is an acid effect and thus has the acid keyword. ...?
Or is there an assumed 'generally' or 'should' in there - as in, "When we designed the PHB powers, we gave all the ones that dealt acid damage the acid keyword, but it cannot be stated with certainty that any time acid damage is delivered, the acid keyword is therefore attached to the power"?
Taking P55 at its word, we would know that a power that deals radiant damage is a radiant effect and thus has the radiant keyword, and so if Overwhelming Strike deals radiant damage thanks to ToL, then Overwhelming Strike is a radiant effect thanks to ToL, and thus has the radiant keyword thanks to ToL.
-Hyp.