What counts as a spell effect for purposes of Side 4 of a Cube of Force?

Question

For reference, Cube of Force Side 4 is:

Spell Effects can't pass through the barrier.

It is unclear to me what counts as a spell effect. I see multiple potential ways of interpreting this:

1. No part of a spell, including its targeting, can go through the cube wall. A pebble with Magic Stone cast upon it that is thrown at the cube stops at the barrier as if it hit a wall. A creature with Haste cast upon it treats the barrier as a wall.

2. No part of a spell, excluding its targeting, can go through the cube wall. A pebble with Magic Stone cast upon it that is thrown at the cube moves through the barrier but loses its magic once it passes through. A creature with Haste cast upon it can move through the barrier but loses Haste. The spells resume after the stone and creature pass back through the wall.

3. Spells can still target inside the cube, but any projectiles or effects created from outside the cube would not go through. The spell itself must state that it has a projectile or area of effect.

Answer 1

Basically any thing in the spell description.

The rules for spells state:

The rest of a spell entry describes the spell's effect.

This refers to the spell’s description. So when Cube of Force says “spell effects can’t pass through the barrier” it means that any effect mentioned in a spell description cannot pass through. Objects and creatures bearing spell effects should be able to move through the barrier, since they are not themselves spell effects, but the spell effects that were active on them cannot pass through, so we conclude the effects on them would either end or be suppressed, which is up to the DM.