Just about the only hard shelled reptile eggs are crocodilian, some turtles, and a few outliers like some geckos. Very few of any of those would be confused with chicken eggs. There also are (hopefully still) wildlife experts as part of border patrol who can and do make those determinations.
That said, there are endangered bird and reptile species that we don't want trafficked and smuggled eggs get rescued by animal control portions of border security unfortunately all the time and they should keep doing their job.
Being pro-tariff can (and should) be like being pro-modern medicine. Targeted use saves lives, but the only difference between medicine and poison is the dosage and treatment vector. Tariffs should be used like every other regulation on the economy, but since Reagan the dosages of every regulation have all been way out of whack either way too low or way too high. There is a place for some protectionism, just not like this obviously.