Summary:

Tools in non-player's hand cannot be rendered as foil instantly.

Steps to Reproduce:

1. Spawn an entity holding a tool.
2. Use the command in the chat box to enchant the tool.

    /enchant @e unbreaking 1

1. Check if the tool has rendered as foil.
2. Save and exit the world.
3. Enter the world again.
4. Check if the tool has rendered as foil again.