On one side, I appreciate your initiative to understand the responsibilities of your job, and on the other, your post has surprised me. Designing KPIs or KRAs for you is the job of your Manager or General Manager, etc. Have you approached your superiors? What is their take on this?
While designing KPIs and KRAs, one needs to study the systems and processes of each department and design customized KPIs. What is applicable to a similar post in another company may not be applicable to your post.
Responsibilities in a Team Lead Role
Your second question is, "What responsibilities do I need to take on in a Team Lead role?" Well, when you were appointed, HR must have provided the Job Description for this position. If you were internally promoted, even then HR might have given you a letter outlining your new job responsibilities. Therefore, why not approach HR for this purpose?
The least you could have done is to download the required material from the internet and show the draft to your managers. Why did you not consider doing that?
General Comments for HR Professionals
The forums of this kind are there to help HR professionals provide advice. To give advice, they are expected to do some basic work. When members raise very basic queries, it brings out the unsaid part of their posts - the disconnect between HR and their staff and the disconnect between superiors and juniors. I hope the learned HR professionals on this forum try to avoid situations like this in their respective organizations.
Thanks,
Dinesh Divekar