Fixing Descriptions That Won't Show Up

First Checks

If holding Ctrl does nothing, work through these before assuming the mod is broken:

• Keybind conflict. Open Options → Controls and search for anything else bound to Ctrl. Sprint, zoom, and freecam mods commonly grab it. Rebind the conflicting action or the description key.
• Wrong screen. Descriptions appear in most inventory-style GUIs, but some custom mod screens do not render them. Test in a vanilla chest or your own inventory first.
• Hovering the wrong thing. You must hover the actual item icon. Hovering a slot border or empty space shows nothing.

If It Worked Before and Stopped

A description set that suddenly goes blank usually means the description data failed to load. Fully restart the game rather than just leaving and re-entering a world — the data is read at launch. If it is still blank after a restart, check whether you recently added or removed mods, since a load-order or data conflict can suppress descriptions.

When Only Some Items Are Blank

This is normal. Not every item has a description, and some are deliberately left without one. If a whole mod's items are blank while vanilla items work, that mod likely has no description support yet, and you will only see generic tag-based text, if anything.