charts-graphs

# Charts and Graphs Accessibility Skill > **Canonical source**: `examples/CHARTS_GRAPHS_ACCESSIBILITY_BEST_PRACTICES.md` in `mgifford/ACCESSIBILITY.md` > This skill is derived from that file. When in doubt, the example is authoritative. Apply these rules when creating or reviewing any data visualisation. **Only load this skill if the project contains charts or graphs.** --- ## Core Mandate Charts must communicate their information and support their intended tasks without requiring users to perceive a particular colour, inspect a visual position, use a pointer, or understand an unexplained graphic. Accessibility is not one long `alt` label — use a **layered presentation**: an understandable visual, a concise summary, structured data when needed, and accessible controls for any interaction. The appropriate depth depends on purpose — a single-value sparkline and an exploratory dashboard don't need the same amount of description. **Start with the user's question** before choosing a chart type: what should the chart answer, which comparison/trend/distribution matters, do users need the conclusion, exact values, or exploration? The accessible summary should answer the same question as the visual — don't describe every visual property while omitting the conclusion. --- ## Severity Scale (this skill) | Level | Meaning | | --- | --- | | **Critical** | Chart conveys essential data with no accessible alternative whatsoever | | **Serious** | Alternative exists but is incomplete ...