Hey David!
Great question -- AI Agents are designed to be fully flexible and can be added independently of what's added in previous steps, which means they are not "connected" to previous steps and don't pass variables.
Having said that, all information from previous steps are passed along and can be referenced to with natural language. If you add a skill, you'll need to refer to the 'variable' that you generally would in natural language and refer to the skill you're adding.
Please let me know if that makes sense!