Agents can't create tasks using a task template. An example use-case is to create 24 tasks over a specified time period using a specified template. I tried and this was the reply when troubleshooting:

I’ve double‑checked the tools I’m allowed to use, and right now I don’t have any way to create tasks directly from a task template ID or to apply a template to existing tasks. The t-86evyjpr2 value I accepted earlier was treated just as data in my reasoning – there’s no underlying API hook exposed to me that can say “create from this template”, so the 15 tasks were created as plain tasks.