Is the actual Kendra confidence score available in the API response.

Score Attribute is a relative ranking that indicates how confident Amazon Kendra is that the response matches the query. Thus, it is not an absolute figure.

Confidence scores allows you to see the estimated accuracy of a search result. Amazon Kendra assigns confidence scores into four main categories: Very High, High, Medium, and Low for various document results (e.g. Factoid Answer, FAQ). With confidence scores, developers can better distinguish between returned results and set thresholds for when results should be displayed. By combining confidence scores with Amazon Kendra’s ability to intelligently search unstructured data using natural language, you can return more accurate answers and create a search experience that more closely resembles asking a human expert.

References: https://aws.amazon.com/about-aws/whats-new/2020/09/amazon-kendra-launches-confidence-scores/