There is only one way to evaluate the contribution of an Augmentation Evoker's DPS — Warcraft Logs. Details and other in-game damage meters will not properly allocate DPS contribution to the Augvoker. Find out more in Warcraft Logs’ article. Warcraft Logs Breakdown Article
Warcraft LogsUnlike in-game damage meters, Blizzard did make combat hooks to allocate damage to the Augmentation so that players can evaluate the contribution and success of having an Augmentation Evoker in the group.
Buffed DamageSince a lot of the buffs are flat damage or flat % effects, the combat hooks can and do attribute the following contribution to the Augmentation Evoker and Warcraft Logs allocates these correctly!
Ebon Might Prescience and Fate Mirror Blistering Scales Breath of Eons Mastery: Timewalker Inferno's BlessingImage from Warcraft LogsWarcraft Logs will show these as sourced from the Augmentation Evoker, and the equal amount of DPS will be taken away from the buffed players. This will allow you to see exactly how much DPS the Augmentation Evoker contributed per player!Image from Warcraft Logs
Combat Hook IssuesHowever, things aren't exactly perfect in the world of damage attribution via the combat hooks. The Blizzard combat hooks don't account for some instances which do occur rather frequently:
Pets! The problem of pets returns again. Damage done via pets and guardians isn't attributed back to the Evoker. This means that if you buff an Unholy DK or Demonology Warlock, they will be showing as doing more damage than their actual contribution, and your contribution will be showing as lower than intended.Accumulator Spells
These are spells which accumulate extra damage and include Ignite, Touch of the Magi, and Execution Read more on wowhead.com