Hmmm, good luck with the condensation, and please let me know how you make out.
My tools (most of them) are in an unventilated metal shed. Although, it is NOT air tight.
I haven't noted condensation on them, but I use them less frequently, and maybe it dissipates before I go out for them. In my previous house we had a unheated/cooled attached garage. Many times in the morning, I would note condensation on my metal tools, and tool boxes.
WD40 helps to ward off rusting. I'll often, but not always wipe my tools down with some before I put them away. Four years like that and most have survived with no ill effects, some tools that haven't been used and wiped down, do have rust spots.
I guess I should get out there with a good oily rag and get to work. Hmmmm where shall I find the ambition?