gdi-rendering-tests

Instructions for writing unit tests for Graphics, Bitmap, GraphicsPath, and Font rendering APIs in System.Drawing. Covers bitmap-based verification, integer/float overload testing, version-guarded test blocks, and FluentAssertions patterns for path-point validation.

Quality

74%

Does it follow best practices?

Run evals on this skill

Adds up to 20 points to the overall score

View guide

Securityby

Passed

No findings from the security scan

Fix and improve this skill with Tessl

tessl review fix ./.github/skills/gdi-rendering-tests/SKILL.md

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 highly actionable with executable, project-specific test patterns and strong structural organization. Main improvements are deduplicating repeated code examples and adding explicit error-recovery guidance when verification fails.

Suggestions

Deduplicate the Graphics_DrawRoundedRectangle_Integer example that appears in sections 2, 4, and 6 by referencing one canonical instance.

Add a short feedback-loop note for when VerifyBitmapNotEmpty or BeApproximatelyEquivalentTo fails (e.g. expected-points recapture steps already in 5.2 could be framed as recovery).

Consider extracting the full VerifyBitmapNotEmpty/VerifyBitmapEmpty helper source and the exhaustive naming list into a references file to reduce inline length.

Dimension	Reasoning	Score
Conciseness	The body is code-forward and assumes Claude's competence without explaining basic concepts, but the Graphics_DrawRoundedRectangle_Integer example recurs in sections 2, 4, and 6, which is a minor tightening opportunity.	4 / 5
Actionability	Provides copy-paste-ready executable C# for real APIs (DrawRoundedRectangle, FillRoundedRectangle, AddRoundedRectangle, DrawString), full helper implementations, exact file locations, and a concrete naming convention covering the common cases.	5 / 5
Workflow Clarity	Clear sequenced patterns (the 4-step verification flow in 3.1, the expected-points procedure in 5.2) with explicit verification checkpoints and a final checklist, but no explicit error-recovery feedback loop for failing tests.	4 / 5
Progressive Disclosure	No bundle files exist, so all content is inline in a ~340-line SKILL.md, but it is well-organized into 9 numbered sections, a location table, a golden-rule callout, and a checklist; over 50 lines so it does not qualify for the simple-skill 5.	4 / 5
	Total	17 / 20 Passed

Description

66%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.

The description is specific and well-scoped to System.Drawing rendering API test authoring, with concrete coverage areas and natural trigger terms. Its main weakness is the absence of an explicit 'Use when...' trigger clause, which caps completeness.

Suggestions

Add an explicit 'Use when...' trigger clause, e.g. 'Use when writing or updating unit tests for GDI+ drawing APIs in System.Drawing.'

Include the synonym 'GDI+' and the phrase 'drawing API tests' to broaden natural trigger-term coverage.

Mention draw/fill pair testing and font-metric range checks to close the minor specificity gaps.

Dimension	Reasoning	Score
Specificity	Names the domain (Graphics, Bitmap, GraphicsPath, Font rendering APIs in System.Drawing) and four concrete coverage areas ('bitmap-based verification, integer/float overload testing, version-guarded test blocks, and FluentAssertions patterns for path-point validation'), with minor gaps such as font-metric and draw/fill-pair coverage not surfaced.	4 / 5
Completeness	The 'what' is clear and concrete, but there is no 'Use when...' clause or equivalent explicit trigger guidance, which per the judging guidelines caps completeness at 3.	3 / 5
Trigger Term Quality	Includes natural terms a user would say ('writing unit tests', 'rendering', 'Graphics', 'Bitmap', 'GraphicsPath', 'Font', 'System.Drawing') but omits the common synonym 'GDI+' and 'drawing API tests'.	4 / 5
Distinctiveness Conflict Risk	The niche is clearly scoped to System.Drawing rendering API tests, distinct from general testing skills; it lacks an explicit trigger phrase that would reduce conflict risk further, so it stops short of 5.	4 / 5
	Total	15 / 20 Passed

Validation

100%

Warnings & errors only

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

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository: dotnet/winforms
Path: .github/skills/gdi-rendering-tests/SKILL.md
Commit: b0a7c95

Reviewed: 1 day ago

Table of Contents

Discovery Implementation Validation

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.