Anti-Summoning Shield

Abjuration
Level: Artificer * 2, Bard * 2, Inquisitor * 3, Sorcerer */Wizard * 2, Summoner * 2
Components: V
Casting Time: 1 Standard Action
Range: medium (100 ft. + 10 ft./level)
Area: 50-ft.-radius
Duration: 1 minute/level (D)
Saving Throw: Will negates
Spell Resistance: yes
  Within the area of effect, this spell impedes the use of spells of the summoning subschool and other effects that summon creatures. Any such spells, spell-like abilities, or similar summoning effects used within the area have a percent chance of failure equals 5% x your Caster Level, to a maximum 75% chance of failure. If the summoning effect already has a percent chance of failure (as is often the case with the summon spell-like ability of outsiders), these percentages stack. This spell does not affect summoners attempting to summon their eidolon, but it does affect summoners casting other summoning spells.