update agents.md with directives for charts

AGENTS.md

@@ -56,6 +56,10 @@ Use these blog posts as inspiration for writing style:
 - Treat figures as first-class content, not decoration
 - **All images/plots must be wrapped as figures** (using `<figure>` with `id` and `<figcaption>`) and every figure must be mentioned in the surrounding text using `<FigRef target="figure-id" />`. Do NOT include "Figure N:" in `<figcaption>` text since the figure environment auto-numbers
 - Interactive elements should reveal insight, not just look fancy
+- **Hover tooltips everywhere**: Add informative hover tooltips wherever possible to surface additional detail (model name, exact values, metadata) without cluttering the chart
+- **Readable text size**: Ensure all text in charts (axis labels, tick marks, legends, annotations) is large enough to read comfortably, comparable to the main body text size
+- **Minimal padding**: Keep internal chart padding/margins small so the majority of space is used for actual content
+- **Discuss every visualization**: Every chart must be cited in the surrounding text with `<FigRef>` and accompanied by 1–3 paragraphs that explain what the chart shows, highlight the key takeaway, and discuss implications
 - Ensure all visualizations work in dark mode
 - Mobile-friendly is mandatory