First World Summoner's Summon Nature’s Ally ability

[Mekkis]

This has been raised before, but the FAQ response was 'question unclear'.

Here is the question I want answered:

Does the First World Summoner's Summon Nature's Ally ability have the same restrictions and durations as the Summoner's Summon Monster ability?

It's not clear whether the ability can be used while the eidolon is out, or whether the ability lasts rounds or minutes per level.