This script does not use notetags, because screw you. Instead, near the top of the script is a place to put lines indicating which skills require which items/weapons. There are some example lines which you may delete.
This script could also be used for any other type of skill which consumes an item, such as gun or bow skills that require ammo, or spells that require reagents. Weapons which are equipped cannot be thrown. If you use this script to make a skill use up an item, it can also still cost MP or TP like any other skill.
It is recommended that you name the skills the same names as the weapons/items being thrown, since the cost is not shown. If you want to show the cost, just put it in the skill's name.
Unlike Final Fantasy, skills appear in your skill list whether you own the item or not, they're just grayed out if you don't have enough items to throw them. This allows you to teach the player these skills any way you want, so for example you might require a character to pay gold at a trainer to learn the ability to throw mythril swords. If you want to dynamically add and remove skills based on the player's inventory, like Final Fantasy, then do that your own damn self with a common event.