Tools are a type of equipment that give you bonuses when executing actions from a certain skill - for example, chopping oak trees is a forestry action and you can use tools such an axe, chainsaw, shears or a range meter to decrease timers, increase random drops, etc.
Yesterday I finished the initial list of available tools for all skills and the "ingredients" required to make each of them. Some tools will be available to make permanently, while others will only be available during certain events.
In the same way as weapons and armor, each instance of a tool that is created is unique, with its own level, quality and modifiers. The higher your toolmaking level, the higher (in average) level your created tools will be. Then luck and the random number generator take their turn. Many of them will be trash to be sold to NPCs, some of them you'll use yourself or sell to other players. A few of them will have very high quality and good modifier distribution and be *very* valuable, either for your own use or to be sold to a richer player.
Good tools for your favorite skills will be the difference between long and short timers, low and high XP gained per hour, low and high resource gathering rate or production. Whether you want to buy some tools and get into the skill of your choice already equipped or make your own tools, become a master toolmaker and sell some of your greatest creations for profit, the tool market should be interesting.