Conciseness

Every line carries tool-specific, non-obvious guidance — exact argument names (`color`, `group`, `detail`, `innerRadius`, `data.comparison_time_range`, `time_grain`) and Rill-specific behaviors (the 'Open in Rill' link, cut-value reporting). There is no padding and no explanation of concepts Claude already knows.

Actionability

The body maps every common question type to a specific chart type with exact channel bindings ('Waterfall Chart with the step on `x` and the signed change on `y`'), names the exact tools to call first (`get_metrics_view`, `query_metrics_view`), and gives a worked title example. This is fully executable instruction-only guidance covering the common cases.

Workflow Clarity

The 'Before you chart' section is a pre-flight checklist (know fields, inspect data, one question, pick grain), and there is an explicit post-hoc feedback loop: 'When the result reports that values were cut, coarsen `time_grain` or lower the `limit`s and create the chart again.' The single task is unambiguously sequenced from inspection through creation to recovery.

Progressive Disclosure

The skill is under 50 lines with no bundle files (references/, scripts/, assets/ are absent) and defers argument shapes to the tool description rather than duplicating them. Sections (Before you chart / Choosing a chart / Titles / Pitfalls) are well-organized and self-contained, which per the guidelines earns a 5 for a short, single-file skill.

Specificity

The description names the domain and several concrete capabilities: "chart a metrics view with the create_chart tool", "which chart type fits which question", and "the pitfalls that produce misleading charts". Coverage is good but minor gaps remain (e.g., no mention of data inspection or title guidance that the body covers), fitting the 'several specific actions; minor gaps' anchor rather than the comprehensive level 5.

Completeness

The 'what' is clear (charting a metrics view, chart-type selection, pitfall avoidance) but there is no 'Use when...' clause or equivalent explicit trigger guidance — nothing states when to invoke this skill. Per the judging guidelines, a missing 'Use when...' clause caps completeness at 3.

Trigger Term Quality

Natural terms like "chart", "metrics view", and "misleading charts" are words users would plausibly say, and the tool name "create_chart" aids matching. Common synonyms such as "graph", "plot", "visualize", or "dashboard" are absent, so it falls just short of comprehensive keyword coverage.

Distinctiveness Conflict Risk

The tie to the "create_chart" tool and "metrics view" gives it a clear niche with low conflict risk against unrelated skills. However, generic chart-selection and 'misleading charts' advice overlaps with general data-visualization skills, so it is 'mostly distinct' rather than a clear level-5 niche.