Conciseness

The body is dense and prescriptive with no explanations of concepts Claude already knows — quotes: "Worker-authored tests, source inspection, and worker screenshots are supporting context only" and "Do not choose a lower-level shortcut merely because it is easier". The main trimmable redundancy is that the eight surfaces are enumerated twice (Surface Selection and Minimum Evidence Floors); that duplication keeps it at anchor 4 ('efficient; minor instances that could be trimmed') rather than 5, and it is well above anchor 3 since nothing reads as padding.

Actionability

For an instruction-only skill the guidance is concrete: exact artifact paths ("<regressions_dir>/<item_id>.md", "<evidence_dir>"), an explicit decision rule ("skipped, missing, or blocked assigned-target results map to passed=false"), a one-recovery policy ("attempt one non-disruptive recovery"), and a full copy-ready report template. Not a 5 because a few directives stay abstract ("Perform the actor workflow from setup to expected result" gives no example of a real exercise) and no concrete sample command or evidence filename is shown; not a 3 because the decision rules, file conventions, and output schema are specific and immediately executable.

Workflow Clarity

The six-step Procedure is clearly sequenced (Prepare setup → Partition lanes → Exercise → Save evidence → Regression ledgers → Synthesize verdicts) with explicit validation checkpoints and a feedback loop: "If setup or a required Needs entry fails, attempt one non-disruptive recovery. If still blocked, fail affected targets with setup evidence", plus the hard checkpoint "Missing required evidence means passed=false" and complete pass/fail mapping rules. This matches anchor 5 (clear sequence, explicit validation, error-recovery feedback, checklists); lane-attribution rules add error handling anchor 5 lacks.

Progressive Disclosure

No bundle files exist (no references/, scripts/, or assets/), and the single file is well-sectioned (Inputs, Surface Selection, Procedure, Minimum Evidence Floors, Report) with no nested references — good structure per anchor 4. It is not a 5 because at ~135 lines some surface-specific detail (per-surface evidence floors) is inlined where a one-level-deep reference file could carry it, and the scoring note's 5-with-sections-only exception applies only to skills under 50 lines.

Specificity

Quotes: "Exercises assigned assertions through browser, API, CLI, background, generated-artifact, migration/data, public-library, or parity surfaces" and "returns per-target verdicts with fresh evidence" — a specific enumeration of eight concrete surfaces plus two well-defined actions. Not a 5 because the core actions reduce to two verbs (exercise, return verdicts) and some phrases ('parity surfaces', 'per-target verdicts') lean on internal jargon rather than plainly stated capabilities; not a 3 because coverage across surfaces is comprehensive rather than 1-2 actions.

Completeness

The 'what' is clear ("Real-surface validation coordinator... Exercises assigned assertions... returns per-target verdicts with fresh evidence"), but there is no 'Use when...' clause or equivalent trigger guidance anywhere in the description. Per the judging guidelines, a missing explicit trigger clause caps completeness at 3 ('has a clear what but when is missing or only weakly implied'); not a 4 because the when cannot be inferred from the text itself.

Trigger Term Quality

Quotes: "browser, API, CLI" are natural terms a user might say, but "validation assignment", "assigned assertions", "fresh evidence", and "parity surfaces" are workflow-internal jargon users would not naturally utter. It matches anchor 3 ('some relevant keywords but missing common variations or synonyms') — natural phrasings like 'verify', 'test the tests', 'check it actually works', or 'real browser check' are absent; not a 4 because the vocabulary skews heavily orchestration-internal rather than user-natural.

Distinctiveness Conflict Risk

Quotes: "Real-surface validation coordinator for engineering validation assignments" and "per-target verdicts with fresh evidence" carve out a distinct niche (independent validation of worker claims via real surfaces) with minimal overlap risk against general testing or QA skills. Not a 5 because generic trigger words like 'validation' and 'testing' could still pull it into overlap with generic test-writing skills; clearly above anchor 3 since the fresh-evidence/verdict framing is quite specific.