What does someone need to know about going from Active Duty to becoming an AGR Recruiter?

I should start by saying that nothing is ever so bad that you have to be a recruiter.
Most recruiters will tell you that.
If you are worried about KD time, that is an Active Component concern. You can become an AGR recruiter as an E4 with no leadership time with BLC complete. And yes, that comes with all the downsides that it implies. In the AGR system, your career progression is all on you and the positions you apply for and the offers you accept or decline. If you choose to remain an AGR recruiter, you will eventually make E7 as a recruiter, and your sum total of military experience will be those few years as an E1-E4 13B, and decades of the same high school and JC visits, making the same drive to MEPS every month, and writing the same contract over and over.
Or, after three years as an AGR recruiter, you can apply for an AGR position at an Artillery Btty or BN, or apply for a different AGR job that allows you to reclass to another MOS.
Either way, you could compete for promotions, apply for different vacancies, get company, BN and BDE staff time, and plan your own career path that could lead to E8 or E9, or OCS.

Disregard what some people say about recruiting. If you are good with people and have a passion to build our nation's military, give it a shot. Attitude makes or breaks someone and as long as you have a can do positive approach, you will do well. Moreover, you will add another feather to your cap because not everybody is cut out to be a recruiter. Reference MSG Kapaun...

That said, AGR recruiting is an interesting position. You will be responsible for the Reserve recruiting mission but you may be tasked to recruit for Regular Army from time to time. I know this because I have several friends who are AGR recruiters. Anyway, I hope my advice was helpful! Best of luck to you.

As a former recruiter, my only advice to you would be don’t do it. Recruiting, no matter what component you do it for sucks. The hours are long, heartbreaks many and rewards few and far between. The recruiter career field is littered with broken marriages, ruined careers and alcoholism.