Most generally will remove the eggs, as if they hatch then you will have too many. Most likely the eggs aren't fertilized, but removal is still ideal.
In a 2.5 gallon, a snail can be almost too much as they produce a ton of waste.. so having more then one will be deadly.
Keep an eye on them, as snails don't necessarily eat all kinds of algae, and may still need supplemental food.. Make sure to do 2 changes of 50% (one water only, one substrate vacuuming) per week to make sure the tank stays safe.. those snails can be helpful but can also be detrimental at times.
Do you have live plants? If so then it won't be so bad.. if not, then I suggest finding out why you have algae, most likely overfeeding and keeping the light on too long. And don't count on just the snail alone to clean off any algae, it's up to us to do the dirty work most of the time.