Conciseness

Nearly half the body is a 'Skillpack activation reporting' telemetry block (UUID generation rules, curl/PowerShell snippets, identity-discovery instructions) that is unrelated to TDD, and lines like "TDD is the red → green loop" explain concepts Claude already knows. The TDD-specific sections themselves are lean, which keeps this above anchor 1's 'severely verbose' but firmly at anchor 2's 'several unnecessary... padded sections'.

Actionability

The loop rules are reasonably concrete ("One seam, one test, one minimal implementation per cycle", "Red before green") but the promised examples — "See [tests.md](tests.md) for examples and [mocking.md](mocking.md) for mocking guidelines" — point to files that do not exist in the bundle, and no worked example is provided inline. This is anchor 3's 'concrete guidance but incomplete; missing key details', not 4, because key guidance is unreachable.

Workflow Clarity

The red → green sequence is present across the 'Rules of the loop' section, but validation checkpoints are implicit: it never instructs running the test to confirm it fails before implementing, or confirming it passes after. This matches anchor 3 ('sequence present but checkpoints missing or implicit'); the sequencing is too coherent for anchor 2 and lacks explicit validation steps for anchor 4.

Progressive Disclosure

The in-file structure is well-sectioned, but the only two references (tests.md, mocking.md) are dangling — no references/ directory or bundle files exist, so following them fails entirely. Per the guideline to score against the actual bundle structure, clearly-signaled references to nonexistent files are worse than anchor 3's 'references present but not clearly signaled', fitting anchor 2's unusable-reference condition.

Specificity

The description names the domain ("Test-driven development") but lists no concrete actions or capabilities — it never says what the skill actually does (e.g., guide the red-green loop, review test quality, place tests at seams). It matches anchor 2 ("Names the domain but actions are minimal or generic"); it is not 3 because no concrete action is stated, and not 1 because the domain itself is specific.

Completeness

It has an explicit "Use when..." clause with concrete triggers, but the 'what' is only the bare label "Test-driven development" rather than a statement of what the skill provides. Anchor 4 ('both what and when; one could be more explicit') is the best fit; anchor 5 requires both to be clearly and explicitly stated.

Trigger Term Quality

Triggers like "build features or fix bugs test-first", "red-green-refactor", and "integration tests" are natural phrases a user would say. It falls short of anchor 5's comprehensive synonym coverage because the most obvious terms "TDD" and "unit tests" are absent, but it is well above anchor 3's 'some relevant keywords'.

Distinctiveness Conflict Risk

The "red-green-refactor" and "test-first" triggers carve out a clear niche with minimal conflict risk, though it could still overlap with a generic 'write tests' or 'unit testing' skill, matching anchor 4 rather than 5.