From Worms Knowledge Base
This utility cannot be used if the player has no airstrike-type weapon available in his inventory, and consequently, it should not exist in cavern levels.
When used, all weapons are locked except airstrikes. When selecting an airstrike weapon, the worm takes out a small laser pointer instead of the usual radio. The pointer can then be aimed like a gun, with a small laser dot indicating which position the airstrike will target.
Firing will not actually call the airstrike, but it will immediately end the worm's turn, and instead of going back to the idle animation, the worm will stay there with the laser pointer in its hand.
If the worm who is using the laser pointer is not damaged or moved in any way, the airstrike arrives automatically after every other team has finished their turn, and inflicts double damage. If the airstrike weapon used drops more than one bomb, the amount of bombs is also multiplied by 1.5. If the airstrike is directional, the direction used is the direction the pointing worm is facing. The airstrike will arrive even if the position pointed by the Target Painter is not visible directly from the sky. If the worm is damaged, nothing happens.
This is a high risk high reward weapon which is best used in a scheme with no or a limited amount of movement utilities (notably Jetpack and Ninja Rope). The player needs to ensure that the worm using the Target Painter is in a safe place, and cannot be easily damaged, otherwise both the Target Painter and the airstrike weapon used are completely wasted. It may even be returned back to its owner if one of the enemy worms are in Girder range, since it would give them the opportunity to influence the position of the airstrike.
There are two main possible uses for this utility. First of all, it can be used for area denial, if the pointing worm is out of range, other players will want to move their worms away from the pointed area. It can also be used to force the enemy to target a specific worm, which can cause a serious dilemna if there is another worm which might become a potential threat during the next turn.