Conciseness

The body is three lines with zero padding or explanation of known concepts ("Load and follow the shared skill at `~/.agents/skills/test-driven-development/SKILL.md`."), and the single provenance comment ("Generated by scripts/agent-harnesses.py; do not edit directly.") is not over-explanation — every token earns its place.

Actionability

The one instruction is concrete and executable (exact path, exact verb: "Load and follow the shared skill at `~/.agents/skills/test-driven-development/SKILL.md`"), but 100% of the actual TDD guidance is delegated to the external file, so key details are entirely missing from the body. Not 4 because the gap is total rather than minor.

Workflow Clarity

This is a single-purpose skill under 50 lines whose single action — load and follow the referenced skill — is unambiguous, satisfying the simple-skill exception; no destructive or batch operations are involved, so no validation checkpoints are required.

Progressive Disclosure

The body contains one clearly-signaled, one-level-deep reference and inlines nothing that belongs in a separate file, but it offers no overview content at all (a pure redirect rather than a "clear overview with well-signaled references"), and the referenced path lives outside the bundle (no references/, scripts/, or assets/ files exist).

Specificity

The description names a domain ("implementing any feature or bugfix", "writing implementation code") but lists zero concrete actions or capabilities. It is above anchor 1 because a domain is named rather than pure abstraction, but below anchor 3 because no concrete actions appear.

Completeness

Only the "when" is present ("Use when implementing any feature or bugfix, before writing implementation code") with no "what" — matching anchor 2's "only 'when' is present without 'what'" exactly. Anchor 3 requires a clear 'what', which is absent.

Trigger Term Quality

"implementing", "feature", "bugfix", and "implementation code" are natural phrases users say, exceeding anchor 2's generic keywords, but the most natural trigger terms for this skill — "test", "testing", "TDD", "write tests" — never appear, so anchor 4's "good keyword coverage" is not met.

Distinctiveness Conflict Risk

"any feature or bugfix" triggers on virtually all software development work, creating high overlap risk with many coding skills. It stays above anchor 1 because it is confined to the coding domain rather than conflicting with virtually any skill across domains.