Regarding Bronzong/Max Potion

[tutti]

Someone posted this thread earlier:
http://pokegym.net/forums/showthread.php?t=170302

The answer confuses me. According to the Compendium (link below), you can't play Max Potion on a pokémon with no damage, even if you discard energy, because (IIRC) discarding energy is a cost, not an effect. Wouldn't the described situation still count as playing Max Potion for no effect? If no, what's the effect you get from playing Max Potion (or if none, why is this an exception)?

Compendium link:
http://compendium.pokegym.net/compendium-bw.html#210

 

[PokePop]

This is different.
This is a case of there being an effect in place that blocks an effect that otherwise would work and meet the requirement of playing the card for an effect.

The fact that it is blocked by another effect doesn't come into play until after the play has initiated.