Wide receiver is an even more extreme case where depending on the player, you could be looking for different drills to gain insight from.
3-cone is a great drill to look at for guys who rely on their ability to separate with their route running. Take Michael Thomas (75% percentile); for instance, he is not the best athlete in the league, but he is a great route runner and can use smarts and change of direction skills to win. Or a guy like Julian Edelman (94% percentile) who people regard as non-athletic for some reason, but fail to realize his quickness and change of direction are elite. It also helps to check to see these players’ level of explosiveness in terms of vertical or broad jumps so you can get a sense of how they are off the snap.
Then you have downfield speedsters like Tyreke Hill (4.29 at pro day) or TY. Hilton (4.34), who wins with great speed and explosiveness, so the 40-yard dash needs to reflect that along with high jumps if possible.
Bigger receivers like Mike Evans obviously win with their size, so the drills for them more often just need to not be disastrous.
And if you’re lucky, you get Julio Jones, who is literally a freak of nature and excels in all aspects.
In the end, know how the receiver wins and see if his athletic traits represent that.
TE: Vertical jump & Broad Jump
With the tight end position becoming more and more athletic, you want an explosive player who can win over the middle of the field.
Ability to explode off the ball, whether they are in-line or flex out, is vital because most tight ends don’t need to be blazers (though I’d take it), but the good speed with that explosiveness is a nightmare. You’d also like to have a tight end that can control the middle of the field to make tough catches in traffic by being able to use their size and rise over defenders.