Yes, I think that you can be too honest. I don't want to sound negative, but a lot of teachers dislike smart kids. Now, before I get figuratively hit in the head by any teachers, I'm sure that many just love smart kids, but many find smart kids annoying. They think that they're being sarcastic, when many smart kids are just literal. Also, a lot of smart kids don't know how to stretch themselves. I had to push my kids - okay, if you already know all that, how can you make it more interesting? What can you do to make it harder? Some kids will do that, but at your son's age, he's pretty young to figure it out and he's also probably going to want to follow the rules and do exactly what the project says-nothing more or less-because he doesn't want to do the wrong thing.
Does the teacher know your son is gifted? Can you meet with her and say, "these activities are great, but would it be okay if my ds did something slightly different to challenge himself?"
I have a friend who has an eight-year old gifted son and when we first started talking a few years ago, I think she thought I was negative at times. She wanted to be open and honest and share her son's gift with the world. However, you do have to use some caution. I know from having two kids go through the system (my college dd and my hs senior dd) that there are good ways and bad ways to communicate to teachers so they don't feel like they're being slammed. Now that my friend has dealt with the school system more, she realizes that sometimes teachers/administrators/other parents can take offense at things that are really completely innocent and honest. She feels like she's being matter of fact, and they feel like she's bragging or insulting them. It's frustrating of course, but you need to deal with this teacher all year and if she is put on the defensive immediately (because really, you are saying it was a bad choice of assignments that taught your son nothing) it won't go well.
Don't get me wrong-I'm on your side and I CRINGE when my gifted second grader comes home with some really stupid assignment he could have done in preschool, but I continue to work with the teacher and school on challenging him and just try to be as positive as I can.
Theresa