Conciseness

The body is dense with operational specifics (token budgets "target 300 tokens inline, flex 200-500, hard cap 600", collision handling, naming conventions) and explains little Claude already knows, matching anchor 4. It is not a 5 because the Phase 1 gate emphasis is repeated in three places ("ENTRY GATE: Phase 2 does not start...", section 1.5, and bolded MANDATORY framing) and "When to Use"/"When Not to Use" substantially restate the frontmatter description.

Actionability

Guidance is highly concrete for an instruction skill: exact AskUserQuestion prompt text ("Proceed with probe? [Yes / Revise hypothesis / Revise criteria / Abort]"), exact artifact path pattern `thinking/probes/{project}/{date}-{slug}-llm.md`, an explicit output format line, and a classification table — anchor 4. It falls short of anchor 5 partly because the migration example invokes `./scripts/run-query-benchmarks.sh`, which does not exist in the bundle.

Workflow Clarity

The two-phase workflow has an explicit entry gate with a loop back to 1.1–1.4 on revision, pre-execution confirm/refute/surprise criteria as a validation checkpoint, a mandatory artifact-persistence step before the exit gate, an AskUserQuestion empty-answer fallback, and a self-transition feedback loop for partial results — matching anchor 5's 'explicit validation steps; feedback loops for error recovery'. Anchor 4 would require missing or merely implicit checkpoints, which is not the case here.

Progressive Disclosure

Four references/ files exist in the bundle, are each signaled with a one-line purpose in a References section, and are one level deep (reference.md contains no nested file references) — close to anchor 5. The gap keeping it at 4 is the dangling `./scripts/run-query-benchmarks.sh` reference in the Usage Examples, which points at a nonexistent bundle file.

Specificity

"Safe-to-fail experiment" and "Two-phase: foreground qualify → background probe → sense result" name the domain and several concrete process actions with only minor coverage gaps (probe types like architecture/library/prompt live only in the body). It matches anchor 4 (several specific actions, minor gaps) rather than anchor 3, which would require only 1-2 concrete actions, and falls short of anchor 5's comprehensiveness.

Completeness

The description explicitly answers both what ("Safe-to-fail experiment for Complex domain problems where cause-effect is only visible in retrospect") and when ("Use when: probe, safe-to-fail, test hypothesis, experiment with hypothesis"), with concrete trigger phrases — matching anchor 5. It also adds negative scope ("NOT for brainstorming... or known cause-effect"), exceeding the anchor-4 example where 'when' could be more specific.

Trigger Term Quality

Trigger list "probe, safe-to-fail, test hypothesis, experiment with hypothesis, Complex domain with hypothesis" includes natural phrases a user would say, but misses common synonyms ("run an experiment", "spike", "validate a hypothesis") and "Complex domain with hypothesis" is Cynefin jargon. This is good-but-not-comprehensive coverage (anchor 4), clearly above anchor 3's 'some relevant keywords with missing variations' but below anchor 5's full synonym coverage.

Distinctiveness Conflict Risk

The description carves out a clear niche (safe-to-fail experiments on falsifiable hypotheses in the Complex domain) and explicitly routes conflicts away: "NOT for brainstorming (use brainstorm) or known cause-effect (use investigate)". This is minimal conflict risk (anchor 5), not merely 'mostly distinct' as in anchor 4.