Pets can equip two kinds of items: Tools, and Keys. A pet can be equipped with up to one of each.
Tools include swords, shields, capes, hats, nailguns and crowbars, to name only a few.
Tools provide pets with bonuses when equipped. These can be bonuses to specific tasks, such as gardening or hunting, or to basic statistics, such as strength or conscientiousness.
Tools typically have a durability rating; as a tool is used, its condition will worsen, until it finally breaks. You can prevent items from breaking by repairing them with Duct Tape, however for very cheap tools it's often more economical to simply replace them when broken.
Keys allow pets to access special locations, monsters, or prey during their hourly activities. For example, the legendary monster Kundrav cannot be approached by a pet unless that pet is holding the Key to Kundrav's Lair.
When a pet accesses the location, monster, or prey allowed by a key, the key is consumed.