Just don't use a fixed script, your natural words will have more impact. Keep it short and sweet, "Amash amendment", "to HR 2397", and I'd avoid mentioning the Nugent amendment, e.g. the recipient might accidentally mis-remember what you said and make a mark on the tally for it, or both.

For extra content I think you'd be better pointing out that the "data about" (rather than "metadata) the phone call you're making right then is being recorded by the NSA.

I just called the offices of Rep. Honda (who's supporting the amendment) and Rep. Eshoo. It was super easy!