Welcome to the community, @Piny! I'm happy to see you and so many others engaging with the agents product.
The behavior that you're describing isn't a bug, per se, as the Configuration Assistant currently only has the explicit ability to specifically create tools. We are planning to expand upon its functionality, though, which will include the power to update or delete existing tools. As soon as we have a timeline for that work, we'll let you know!
In general, I agree that there's a ton of potential for this kind of AI assistance across different parts of the product. Building an agent function is mostly analogous to creating a workflow, for example, which is a product area that a lot of builders find intimidating. Then there's the app-building AI that we're working on, as well! Exciting times. 