Castilliano wrote:
Summoner's Precaution has an odd phrase, suggesting that even when the spell makes the Eidelon unmanifest, it'll still take any other adverse effects that accompanied the damage.
But yeah, that spell falls into the (unfortunate) "must have" category.
I'd carry several wands by higher levels, buying a new one each time I used my set, just in case. That 2nd level spell could spare you tons of damage on a BBEG crit.
A wand of Summoner's Precaution is a must have item to any build.
Wand of rapid adaptaion also proved to be quite valuable.