recursica-skill-data-visualization

Decide the story first, then pick the simplest chart that tells it. Use lines or areas when slope and rate of change matter, bars or columns for values at moments, and avoid pie charts except for two highly differentiated segments totaling 100%.

Pie and donut charts are effectively banned except for two segments — rarely three — with a clearly visible difference in value, and segments must total 100%. Never repeat the chart's own value inside the donut hole.

No library is house-endorsed yet. Check the project for a declared charting library first; if none exists, prompt the user to choose a genuinely open-source, React-first, themeable library with no competing theme provider.

A truncated baseline exaggerates small variance and makes honest data look volatile, while logarithmic scales mislead because readers do not perceive orders of magnitude as even steps. Both rules keep charts honest by construction.

Never rely on color alone — add patterns, labels, and legend icons so the chart survives a black-and-white rendering. Provide an accompanying data table, at minimum available, so screen reader users can reach the underlying values.

Do not chart differences too small to see, such as 51% versus 49%, and do not visualize substantially incomplete data. A number with typographic emphasis or a plain table is often the simpler way to tell the story.