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visualizing-change-over-time

Helps PostHog engineers and agents pick the right chart when a request is about visualizing change over time, before/after comparisons, or period-over-period movement while building UI with @posthog/quill-charts (dashboards, reports, the mcp_analytics frontend, custom visualizations). Use when a user asks how something "changed", "moved", "grew", "dropped", "improved", or "regressed" between two points or periods, or mentions "before/after", "period over period", "week over week", "delta", "slope graph", "slopegraph", or comparing many series across two snapshots. Surfaces both the `SlopeChart` quill component and the native `ChartDisplayType.SlopeGraph` insight display as options.

72

Quality

88%

Does it follow best practices?

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SecuritybySnyk

Passed

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SKILL.md
Quality
Evals
Security

Quality

Content

82%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

The body is actionable and well-structured: a decision table, executable code, key options, and a clear two-path scope note. It is concise and avoids padding, with only minor organization and tightening opportunities in the scope-note detail.

Suggestions

Consider moving the detailed Scope Note (feature-flag gating, backend runner paths, API usage) into a short reference file and keeping a one-line pointer in SKILL.md to tighten conciseness and progressive disclosure.

Trim the opening paragraph, which restates the frontmatter description, to reduce token overlap.

Add a one-line 'When in doubt, default to TimeSeriesLineChart' fallback so the selection workflow has a single unambiguous default.

DimensionReasoningScore

Conciseness

Lean, assumes Claude's competence, and avoids explaining known concepts; the intro paragraph lightly restates the description and the dense scope note could be marginally trimmed, so just below the top anchor.

4 / 5

Actionability

Provides copy-paste-ready TSX for SlopeChart, concrete config options, exact file paths, feature-flag names, and a decision table — fully executable guidance covering the common cases.

5 / 5

Workflow Clarity

The decision table gives a clear shape→chart→why sequence and the scope note cleanly routes between the two render paths; it is a selection skill (no destructive/batch validation needed), but the final choice is deliberately left to the user, keeping it just below unambiguous.

4 / 5

Progressive Disclosure

Well-organized into distinct sections with a one-level-deep, clearly signaled reference to the charts AGENTS.md; no bundle files exist, and the fairly long inline scope note is the main organization gap versus the top anchor.

4 / 5

Total

17

/

20

Passed

Description

95%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A strong description: third-person voice, explicit what-and-when, and rich trigger-term coverage with synonyms. The only minor gap is that the concrete actions are largely variations of 'pick/surface a chart' rather than a broad set of distinct operations.

DimensionReasoningScore

Specificity

Names the domain and concrete surfaces (dashboards, reports, mcp_analytics frontend) plus specific components (SlopeChart, ChartDisplayType.SlopeGraph), but the core action is essentially 'pick the right chart' / 'surface options' — comprehensive trigger coverage rather than many distinct concrete actions, so just below the top anchor.

4 / 5

Completeness

Explicitly answers both 'what' (helps pick the right chart; surfaces SlopeChart and ChartDisplayType.SlopeGraph) and 'when' via a concrete 'Use when...' clause with specific trigger phrases.

5 / 5

Trigger Term Quality

Comprehensive natural-term coverage including synonyms ('slope graph' / 'slopegraph') and many phrases a user would naturally say ('changed', 'grew', 'dropped', 'before/after', 'week over week', 'delta').

5 / 5

Distinctiveness Conflict Risk

Clear niche tied to @posthog/quill-charts change-over-time visualization with slope-graph emphasis and distinct triggers, minimizing overlap with other skills.

5 / 5

Total

19

/

20

Passed

Validation

93%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

relative_links

Relative link issues: 2 suspicious

Warning

Total

15

/

16

Passed

Repository
PostHog/posthog
Reviewed

Table of Contents

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