Adjusting Gear Actuation
I'm not sure what you're comparing the effort to, but typically the front derailleur requires more cable pull to actuate, in comparison to shifting in the rear.

Adjusting Shimano Front Derailleurs

Adjusting Shimano Rear Derailleurs

It could be that you need a bit of slack removed from the cable, but without photos, it's hard to say.

Front shifting explained