I'll just quick throw this in, that using too few descriptors could possibly be a problem, or at least open the door for it.
I've not been able to get any better fund options added where I work, but I can
see where it could go astray. My employer's 401k exclusively offers American Funds mutual funds.
But, simply asking for "index fund mutual fund options" may not work so well. For example, American Funds does
offer Vanguard's Total Stock Market fund - at an ER as high as 1.50%.
And a "low-cost" request could get you a money market fund that's yielding a whole lot of nothing.
Just something to keep in mind. (And best of luck to you in this. Hopefully it turns out well.
Edit: Another thought to throw in: If the funds would benefit everyone there, that could be a big help, and it would just be very nice for anyone else using the plan. (For example, if you
need a little bit of small-cap to offset a heavy loading of large-cap elsewhere in your portfolio, that would mainly benefit you
.) If you want to add some Vanguard LifeStrategy funds, for example, they offer a very simplistic, diversified, and inexpensive way of saving money for retirement, especially for the person who doesn't know much about investing.