Quick question about applying for a CFI certificate and an AGI (Advanced Ground Instructor) certificate.

Here's what I have done so far: FIA written test, the AGI written test and the FOI written.

I want to get my AGI certificate first and it sounds like all I need done is the AGI + FOI written, an application on IACRA and an appointment with the FSDO and it's done.

But, if I wanted to take my CFI checkride after this do I have to take the FOI again or does the one FOI test count? Or does the AGI certificate I would currently hold count as the fundamentals of instructing portion of the checkride?