Assigning actions to a topic
Key Takeaway
An action you add from the Asset Library becomes the agent's own independent copy, so later changes to the library action don't reach that agent. By default, the added action goes into both the subagent's action definitions and its reasoning actions, where the LLM can select it.
In Agentforce, a subagent (called a topic before April 2026) is one job an agent can do. Actions are the tools the agent uses to do that job. Assigning actions to a subagent decides which tools the agent has for that job and whether each action runs on a fixed rule or only when the LLM chooses it.
Subagents and actions
The rename from topic to subagent did not change functionality. You may see both terms during the transition.
A subagent holds two kinds of things: reasoning instructions, which guide how the agent reasons, and actions, which are the tools available for that job.
Actions are how an agent gets things done in Salesforce. Each action gets information or performs a task by calling Salesforce functionality, such as a flow or prompt template. Salesforce provides standard actions for common tasks. You can create custom actions for your own business use cases.
A service agent has an Order Support subagent. Its reasoning instructions tell the agent to ask for an order number before it looks anything up. Its actions are the tools for that job. One action gets an order's status by calling a flow. Another action drafts a delay apology by calling a prompt template.