Build a workflow agent by connecting one or more Agent blocks to the steps it needs. Each Agent block sends messages to a model, lets it call configured tools, and returns a result for later blocks.
Build a workflow agent
A simple agent reads an input, scores it, and returns the score:
- Add an Agent block after a Start trigger.
- Select a Model. In Messages, use a system message for the task and rules, and a user message for the input, such as
<start.input>. - Add the tools or context the task needs, then run the workflow and inspect the result.
Without Response Format, later blocks read the answer as <agent.content>. Model, token, tool-call, and cost details are also available. The example requests a structured score, so its Response block reads <agent.score> after successful JSON parsing. See the Agent reference for model selection, settings, and outputs.
Add capabilities
| Need | Configure |
|---|---|
| Take an action | Attach integration tools, custom tools, MCP tools, or another workflow as a tool. The model decides which available tools to call. |
| Follow a reusable procedure | Select skills, such as a lead-scoring rubric. The agent sees their names and descriptions, then loads instructions when they apply. |
| Answer from your documents | Add the Knowledge tool and select the knowledge base to search. |
| Read a file | Use the Agent block's Files input with a model that supports the file type. |
| Remember earlier runs | Configure memory and a conversation ID. The memory mode controls which history reaches the model. |
| Return fields for later blocks | Set Response Format to request a JSON shape, then reference successful structured fields directly, such as <agent.tier>. Provider support and malformed-output behavior vary. |
Tools and skills need a compatible model and the required workspace, credential, and organization access. Adding a skill supplies instructions; adding a tool gives the model an action it can call.
Choose where an action runs
Use a separate workflow block when an action must be attempted whenever that path runs. Attach it as an Agent tool when the model should decide whether it is needed. For example, a lead-scoring agent might search for missing company information, while a Google Sheets block records every score that reaches it.
The same integration can serve either role. See Choosing what to use for the differences among fixed steps, Agent tools, custom tools, MCP connections, workflows as tools, and skills.