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testland/timezone-test-matrix-builder

Use when a codebase needs time zone, DST and leap-year test coverage derived from its own date and time code. Finds where times are stored, computed, displayed, scheduled or billed, picks the edge cases that matter and writes test stubs using the language's fake-clock library.

Quality

86%

Does it follow best practices?

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Overview
Quality
Evals
Security
Files

Quality

Content

81%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.

A well-structured, largely executable multi-step skill with an exemplary validate-and-re-run checkpoint and proper offloading of the test catalog to a real bundle reference. The gaps are minor: some redundancy in the worked example, a broken brace-glob in the inventory grep, a comment/assertion mismatch in one emitted test, and harness paths that resolve only against a companion skill's bundle.

Suggestions

Actionability: replace the non-functional brace glob with explicit --include flags or a find/xargs pipeline (e.g. multiple --include='*.py' --include='*.js' ... or grep -rn ... --include='*.{py,js}' via shell-expanded braces), and fix the Step 5 fall-back example so the comment, the frozen instant, and the asserted period duration agree (freeze just past 06:00Z on 2026-11-01, or assert the 25-hour Nov 1-2 window).

Progressive disclosure: make the harness file paths unambiguous by prefixing them with the owning skill (e.g. fake-clock-testing/references/python.md) or inlining a minimal per-language harness snippet in this bundle so the links resolve regardless of companion-skill availability.

Conciseness: compress the Worked Example to only the new information (the end-to-end trace of one touchpoint) and drop its restatement of Steps 1, 3, 5, 6, and 7.

DimensionReasoningScore

Conciseness

Efficient throughout - terse tables, no re-teaching of concepts Claude knows - but the Worked Example section largely reiterates Steps 1, 3, 5, 6 and 7 already covered above it, which could be trimmed.

4 / 5

Actionability

Mostly executable: concrete grep commands, a category-to-test mapping table, a matrix.yaml template, and copy-paste freezegun tests with run commands. Minor gaps keep it from fully executable: the inventory grep's brace glob "--include='*.{py,js,...}'" is not valid grep syntax, and the Step 5 fall-back test's comment ("Period from Nov 1 00:00 to Nov 2 00:00 ... 25 hours") contradicts its month-duration assertion, with 2026-11-01T05:30Z actually falling just before New York fall-back (06:00Z), not past it.

4 / 5

Workflow Clarity

Seven clearly sequenced steps with an explicit validation feedback loop in Step 6: run the emitted files, and "If a case errors instead of asserting, the fake-clock wiring is wrong - fix the harness mapping (Step 3) or add the missing TZ / zone ... and re-run until the matrix is green" - matching the anchor with error-recovery loops for a batch operation.

5 / 5

Progressive Disclosure

The per-category catalog is properly split into the real one-level-deep reference references/test-catalog.md with clear signaling, and per-language harness detail is delegated rather than inlined. However, the six harness paths (references/python.md through references/libfaketime.md) do not exist in this skill's bundle and are attributed to the companion skill fake-clock-testing only via the table's column header, creating minor navigation ambiguity.

4 / 5

Total

17

/

20

Passed

Description

87%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 with an explicit "Use when" clause carrying concrete trigger phrases and a multi-action statement of capability. Its only weaknesses are one vague phrase ("picks the edge cases that matter") and a few missing natural synonym variants of its trigger terms.

DimensionReasoningScore

Specificity

Lists several concrete actions - "Finds where times are stored, computed, displayed, scheduled or billed", "writes test stubs using the language's fake-clock library" - but "picks the edge cases that matter" is a soft, non-concrete phrase, leaving a minor coverage gap versus the comprehensive anchor 5.

4 / 5

Completeness

Explicitly answers both questions: "Use when a codebase needs time zone, DST and leap-year test coverage derived from its own date and time code" gives concrete trigger phrases for when, and the inventory/pick/write-stubs actions state what it does.

5 / 5

Trigger Term Quality

Natural terms users would say are present - "time zone", "DST", "leap-year", "test coverage", "date and time code" - but common variants like the one-word "timezone", "daylight saving", or "TZ" are missing, so coverage is good rather than comprehensive.

4 / 5

Distinctiveness Conflict Risk

Occupies a clear niche - deriving timezone/DST/leap-year test matrices from a codebase's own date/time code with fake-clock harnesses - with distinct triggers and minimal overlap risk against generic testing skills.

5 / 5

Total

18

/

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.

Validation — 15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

referenced_paths_exist

Referenced path issues: 8 missing

Warning

Total

15

/

16

Passed

Reviewed

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