You can delete an agent by selecting the Delete option from the Agents View. When you select an agent and click the Delete option, the Delete Agents pane displays a list of the assets associated with the agents. You can choose to delete assets associated with the agent selected for delete, from the list of assets.
When you delete an agent without selecting the associated assets, then the assets are considered as agentless assets in the system. You can perform raw data based collection on agentless assets.