It was all captured on HBO's "Hard Knocks" -- when defensive coordinator asked the linebacker to come up with a list of weaknesses he learned about his teammates during his time in Philly.

Kendricks didn't even hesitate -- putting together a Eagles cheat sheet like a double agent ... and then presented all of his info during a team meeting before they clashed in last week's preseason game.

Here's the info ...

"Uh, let's start with Nick Foles. Playing with Nick Foles, I realized on his long balls, his deep balls, he has like a teardrop effect. He's tall and he likes to drop that literally from the sky. So corners, and the timing's just a little slower on that ball coming in."

"86 [Zach Ertz], I think, is the best receiver on the team. Notice I said 'receiver.' When it comes to blocking, you f*cking hit his ass over and over, he doesn't want any smoke."

"Big V, Vaitai. He's so big that his size allows him to do what he does. You see, but he doesn't have the quickest feet and he's not the strongest. He doesn't trust his feet at all. You get on him, his confidence will go down."

Look, we get it ... sometimes teams will bring in players for their knowledge about their former team -- but this one felt especially snitchy.