The usefulness of the skill is rather lessened because we have to be told when to use it.
No, you don't. Do you think BRDs should have to be told when to use Paeon, too?

It shouldn't be difficult to identify a party member using a lot of AoE attacks, and these are the ones likely to appreciate some more TP.

WAR spamming Overpower? BRD spamming Wide Volley? DRG spamming Doom Spike? There you go, use it on them.