I would worry that it could get to warm in the summer and would also worry about large predators like stray dogs, coyotes even smaller ones like racoons and opposum.
But I'm in "worry-wart" mode today as my first time ever day-olds are due to arrive next week!
Sorry, but I have to agree with everyone else. A tent will do nothing to protect your flock, It wont even keep them in. Sorry but it is a bad Idea overall.
I think the tent will not work well. Tent fabric degrades really fast in direct sunlight and it is surprisingly fragile to things like raccoon, stray dog, or rat teeth. As an emergency two or three day thing it might work, but as a permanent home I think you'd be making a mistake.