Aid from the Cowl — ruling 1

If the revealed card is not a permanent card or if you choose not to put it onto the battlefield, you may put it on the bottom of your library. If you don't, it remains on top of your library.

Aid from the Cowl — ruling 2

A permanent card is an artifact, creature, enchantment, land, or planeswalker card.

Aid from the Cowl — ruling 3

If a permanent put onto the battlefield this way has an ability that triggers at the beginning of your end step, it won't trigger during this end step.

Aid from the Cowl — ruling 4

Revolt abilities check only whether a permanent you controlled left the battlefield this turn or not. They don't apply multiple times if more than one permanent you controlled left the battlefield. They don't check whether the permanent that left the battlefield is still in the zone it moved to.

Aid from the Cowl — ruling 5

Revolt abilities don't care why the permanent left the battlefield, who caused it to move, or where it moved to. They're equally satisfied by an artifact you sacrificed to pay a cost, a creature you controlled that was destroyed by Murder, or an enchantment you returned to your hand with Leave in the Dust.

Aid from the Cowl — ruling 6

Tokens that leave the battlefield will satisfy a revolt ability.

Aid from the Cowl — ruling 7

Energy counters aren't permanents. Paying {E} won't satisfy a revolt ability.

Aid from the Cowl — ruling 8

All cards in the Aether Revolt set with triggered revolt abilities use an intervening "if" clause. A permanent you controlled must have left the battlefield earlier in the turn in order for these abilities to trigger; otherwise they do nothing. In other words, there's no way to have the ability trigger if no permanent you controlled has left the battlefield that turn, even if you intend to have one do so in response to the triggered ability.

Aid from the Cowl : règles, fonctionnement et interactions (MTG)

Aid from the Cowl is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Revolt — At the beginning of your end step, if a permanent left the battlefield under your control this turn, reveal the top card of your library. If it's a permanent card, you may put it onto the battlefield. Otherwise, you may put it on the bottom of your library.

How it works : Aid from the Cowl

Original English text — Wizards of the Coast / Scryfall

#1February 9, 2017· Wizards of the Coast
If the revealed card is not a permanent card or if you choose not to put it onto the battlefield, you may put it on the bottom of your library. If you don't, it remains on top of your library.
No other card is named in this ruling.
#2February 9, 2017· Wizards of the Coast
A permanent card is an artifact, creature, enchantment, land, or planeswalker card.
No other card is named in this ruling.
#3February 9, 2017· Wizards of the Coast
If a permanent put onto the battlefield this way has an ability that triggers at the beginning of your end step, it won't trigger during this end step.
No other card is named in this ruling.
#4February 9, 2017· Wizards of the Coast
Revolt abilities check only whether a permanent you controlled left the battlefield this turn or not. They don't apply multiple times if more than one permanent you controlled left the battlefield. They don't check whether the permanent that left the battlefield is still in the zone it moved to.
No other card is named in this ruling.
#5February 9, 2017· Wizards of the Coast
Revolt abilities don't care why the permanent left the battlefield, who caused it to move, or where it moved to. They're equally satisfied by an artifact you sacrificed to pay a cost, a creature you controlled that was destroyed by Murder, or an enchantment you returned to your hand with Leave in the Dust.
No other card is named in this ruling.
#6February 9, 2017· Wizards of the Coast
Tokens that leave the battlefield will satisfy a revolt ability.
No other card is named in this ruling.
#7February 9, 2017· Wizards of the Coast
Energy counters aren't permanents. Paying won't satisfy a revolt ability.
No other card is named in this ruling.
#8February 9, 2017· Wizards of the Coast
All cards in the Aether Revolt set with triggered revolt abilities use an intervening "if" clause. A permanent you controlled must have left the battlefield earlier in the turn in order for these abilities to trigger; otherwise they do nothing. In other words, there's no way to have the ability trigger if no permanent you controlled has left the battlefield that turn, even if you intend to have one do so in response to the triggered ability.
No other card is named in this ruling.