How do I Update DCL field through a workflow agent?

How to dynamically update a DCL field using variables/parameters in a Workflow Agent? I successfully updated a DCL field with a static value using the Business Object tool within a workflow agent. But when I try to pass a dynamic value using a variable/parameter in my prompt, the update fails.

Can I achieve this solely through prompt configuration, or do I need to map parameters explicitly in the workflow setup?

Below is the prompt I am currently using.

Step 2.5.1 Update my custom product using the tool 'Triage_SR_Asset_Update'

1. always invoke:
   Triage_SR_Asset_Update({"ModelDCL_Id_c": {{ProductId}},"ProblemDescription": "DEBUG ProductId={{ProductId}}"})