Scrying orb help eve scout for vision wards in the bushes they usually place them, so you know if you can use that gank rout or another, thats why it fits her so much.
Anyway, as an Evelynn player, i see some flaws in your guide. First of, you suggest using zero magic resistance, following the example full build and runes choices, that means any mage will eat you, before you even approach them, dont forget eve is close to medium range champ and she dont have the burst to finish off opponents fast enough, thats why she needs durability. The Block mastery is mostly useful when you are playing in lane and constantly being hit by enemy champion, which is not the case when jungling. You also pick Enchanted Armor , notice it boosts only bonuses you get to armor and resistance, yet all the bonuses you get following your full item build and runes choices are armor runes and omen, which makes this mastery pretty inefficient too. Focusing on AP, only works well if you pick items that gives you a great deal of that stat, picking Archmage and Arcane Blade while only having shortage of it, isnt that great. For example Archmage will give you only 15ap if you have 300 ap, which your items of choice would eventually reach, much better would be if you invest those points in Brute Force which will give you even more AD, which will also benefit your basic attack and they are essentially important for you as a jungler. Arcane Blade would reach 15 magic damage on hit the most, while Martial Mastery will give you 4 AD from the very start of the game. You suggest starting with blue golems and even smiting it(which gives you pretty much no extra benefit). Its much better if you use your 1st smite on one of the side camps, for the respective buff(they help you great deal when killing monsters), or even smiting red for the hp reg and its generally advised you always start from bot lane, cus there you can get a better leash. Anyway, if you rly insist for early counter-jungle gank, you can still start from Gromp, or the Krugs then pick your blue/red buff and arrive at the enemy camp in a timely manner.

So you say for your strat to get blue then go place a ward on red and wait....but your starting items are machete x2 hp pots and blue trinket, where is this ward you speak of?

This is great, but why do you use Scrying Orb? Also, I like your guide, upvoted

Dude, have you ever tried AD Evelynn? I mean, with Brutalizer, Blade of The Ruined King, and Randuin's/Spirit Vissage? It's way better in my opinion, your "E" AD ratio is better than the AP one. Test it! Maybe using one AP quint to maximize your early game impact.