Cirk's Ammocheck 

Do you find yourself forgetting to stock up on arrows, shot, or throwing weapons before you go running off to meet your party or sneak into an instance? Then maybe you need Ammocheck! Ammocheck checks the amount of whatever ammunition you currently have equipped (arrows, shot, or thrown) whenever you finish trading with a merchant or start talking to a flight master and gives you a warning message if the level falls below your preferred limit. Ammocheck can also be enabled or disabled on a per character basis, and automatically disables itself for any class that can't use thrown or ranged weapons.

Ammocheck will only check for ammunition in your bags that works with the ranged weapon you currently have equipped (i.e., bullets for guns, arrows for bows and crossbows, or other thrown weapons if you have a thrown weapon equipped). So if you switch between weapon types you may see a warning from Ammocheck about your current weapon ammunition even when you have enough ammunition for your other (not equipped) weapon. And if you don't have a ranged weapon equipped at all, Ammocheck won't give you any warnings!


Ammocheck slash commands
Ammocheck supports the following options for those classes that can use it:

/ammocheck help shows these options.
/ammocheck on enables Ammocheck for your current character (the default until you change it).
/ammocheck off disables Ammocheck for your current character.
/ammocheck set # or simply /ammocheck # where # is a number, sets the count of ammunition below which Ammocheck will give you warnings.
/ammocheck status shows you whether Ammocheck is enabled and what your current limit is.