Area seems to be written oddly. "Radius-burst burst" doesn't make any sense to me. Shout and greater shout have cone-shaped bursts.
Spells like web and silence have a clearly-defined radius (10 ft, 20 ft respectively)). . Burst makes more sense since the effect isn't something that lingers. I recommend changing to a "sphere-shaped burst."


From the SRD:
A burst spell affects whatever it catches in its area, even including creatures that you can’t see. It can’t affect creatures with total cover from its point of origin (in other words, its effects don’t extend around corners). The default shape for a burst effect is a sphere, but some burst spells are specifically described as cone-shaped. A burst’s area defines how far from the point of origin the spell’s effect extends.
Debby