docs: add minimal Agent instantiation example to docstring

[Arnav-Ajay]

What this PR does

Adds a minimal, runnable example to the Agent docstring showing the recommended import path and basic instantiation.

Why

New users often struggle with where to import Agent from and what the minimal setup looks like. This keeps the reference concise while improving clarity.

Scope

• Docstring only
• No behavior changes

[seratch]

Thanks for sending this patch. However, we don't need this small change for now.

[Arnav-Ajay]

Thanks for the quick review and clarification!
Understood — appreciate you taking the time to look at it. Happy to contribute in other areas if a more concrete docs or examples need comes up.