Tool of the Trade is a short side-quest you should complete if you want to use the Unappraised Items you gather in the Temple Ruins. Tool of the Trade doesn’t have any requirements, and you can activate it and also finish it the moment you reach Ruffian.
For Tool of The Trade; however, you need to find and collect a Loupe, which can be hard to locate if you don’t know where to look for it.
A loupe is also known as a magnifying glass.
Our Lightning Returns: Final Fantasy XIII Tool of the Trade walkthrough explains where to find Elmer’s Loupe, and what can you do with the Unappraised Items you might have in your inventory.
Description: “In Ruffian, Lightning meets a young man who speaks in a strange code. Elmer first came to the Dead Dunes to unlock the secrets of the ruins, and although he has given up on his research, he still knows a great deal about them. Lightning may help rekindle his motivation if she finds his old appraising tool, the loupe. Hint: The bandits discard their garbage in the Atomos’s Sands area.”
Location: Dead Dunes
Rewards: 400 Gil, Maximum HP + 50, Strength + 2, Magic + 4, Retro Scopes Adornment
When you get to Ruffian, or the Den of Thieves, check the second floor of the camp and look for a small boy wearing some strange glasses.
Elmer also wears a brown jacket, and he stands on a small balcony. After you talk to him, Elmer tells you that he lost his Loupe and he wants you to find it.
Exit the building and open your map. Notice the pass north from Ruffian and observe that it connects the Den of Thieves, and the sub-area known as Atomos’s Sands.
Follow the pass and when you exit to Atomos’s Sands head north looking for an elevated platform similar to a tower. Climb the ladder and while standing on top of the structure facing south-east, you should see a glowing area on the ground.
You have to pay close attention and make sure you are looking down the hill. If you examine the small patch you will recover Elmer’s Loupe. Next, bring the item to Elmer and he will agree to take a look at the unappraised items in your inventory.
The unappraised items in Lightning Returns: Final Fantasy XIII, are in fact unidentified items you can find in most ruins, or by killing lizards.
They can be medals, Pilgrim’s Cruxes, or even potions. After you collect them, make sure you ask Elmer to identify all these items for you.