This feature helps you easily get needed information from users. One way to get information is to ask the user little by little. The second way is that the user can type the information at once. All you need to do is have information in the entity and you can solve both situations easily.
Example 1: Directly to interaction Big trees
Example 2: Ask for information about size
Create an entity with information
Create intent linked to the entity
Prepare interactions: create interactions for small/middle/big tree offers
Add intent to interactions
Add entity to interactions
Set value of entity (depends on the size of trees in interaction)
Create interaction which do not get the size of a tree. small/middle/big tree offers
Add intent and entity to interaction
Set value of entity to optional
Add also handlers for responses.