Using Commas with Equal Adjectives
Insert a comma between two or more adjectives that equally modify the same noun.
A skinny, alert coyote howls at the moon.
(The adjectives skinny and alert equally modify coyote, so a comma should separate the adjectives.)
Many hungry coyotes searched for food.
(The adjectives Many and hungry don't equally modify coyotes, so a comma should not separate the adjectives.)
If you can switch the order of the adjectives, you know they are equal.
An alert, skinny coyote howls at the moon.
Hungry many coyotes searched for food.