The Number of Shapes agent expresses a preference for a specific proportion of the shapes in a design to be of a certain zoneType.
A design's unfitness as evaluated by AgentNumShapes is a measure of how much the proportion of shapes of a specific zoneType in a design differs from the desired proportion.
The Number of Shapes agent is good for determining the desired mix of zoneTypes in your designs. If you find that constraints you have placed on other agent types makes a certain zoneType less or more likely to appear than you wish, you may rectify that by adjusting the preferences of this agent.
If you choose to edit this agent, you will be presented with this dialog box.