IMO if doing this, you should avoid text in the charts entirely (as the title can sometimes I think lead the models astray, such as the clustering title I think will bias it to find clusters even if none exist). Presuming you are the one making the chart and not just prompting with another image.

I believe the text in the image will be more prone to misinterpretation that direct text in the prompt anyway, https://andrewpwheeler.com/2024/07/16/using-genai-to-describ...