Unchained summoner and natural attack modifier evolutions

[primevalivy]

If you have an unchained eidelon with multiple of the same attack and but a modifier (I.e. Improved damage, grab, or reach) does it apply to all instances of the attack or only one.

For example if it has 3 tentacles and reach does it have one with reach and two without or 3 with reach?

[Saethori]

Wording is key here.

Improved Damage wrote:

One of the eidolon's natural attacks is particularly deadly. Select one natural attack form and increase the damage die type by one step. This evolution can be selected more than once. Its effects do not stack. Each time an eidolon selects this evolution, it applies to a different natural attack.

Grab wrote:

An eidolon becomes adept at grappling foes, gaining the grab ability. Pick bite, claw, pincers, slam, tail slap, or tentacle attacks. Whenever the eidolon makes a successful attack of the selected type, it can attempt a free combat maneuver check. If successful, the eidolon grapples the target. This ability only works on creatures of a size one category smaller than the eidolon or smaller. Eidolons with this evolution receive a +4 bonus on CMB checks made to grapple.

Improved Damage and Grab both specify types or forms of attack. In situations like this, if you apply it to claw, it affects all claw attacks the eidolon is capable of.

Reach wrote:

One of an eidolon's attacks is capable of striking at foes at a distance. Pick one attack. The eidolon's reach with that attack increases by 5 feet.

In this case, Reach specifies just one attack, singular. If you apply it to a claw, you need to actively specify which claw, and it applies only to that one. Any other claws remain reach-less.

[Quotes are from original Summoner, but the Unchained Summoner uses effectively the same wording]

[primevalivy]

Thanks!