Conciseness

The ~60-line body is lean with no re-teaching of concepts Claude already knows; even the framing lines ("A cheap experiment beats confident reasoning, and the source on `HEAD` beats memory") are compact behavioral rules, not padding. Every token earns its place, matching the 'lean and efficient; assumes Claude's competence' anchor rather than the score-4 anchor's 'minor instances of over-explanation'.

Actionability

Per the instruction-only scoring note, guidance is thoroughly concrete: each step names its object and success criterion ("Classify each as Verified, Plausible, or Risky"; every command/tool/port "comes from a `file:line` in the repo, never from training data"; "Run `<plugin root>/scripts/prose-lint.py` on it"; "After about three rounds, surface that the problem needs reframing"), and the exact reference file to read is pinned to each step. There are no missing key details for a process skill of this genre, so it sits at the 'fully actionable' anchor rather than 'minor gaps'.

Workflow Clarity

Ten numbered steps are clearly sequenced with explicit validation checkpoints and feedback loops: "A refuted assumption sends you back to step 2. Never patch around it", the loop-or-commit rule with a three-round reframing trigger at step 8, an evidence-based Definition of done that "sends you back to the step that produces it", and a gated step 10 requiring explicit approval for deviations. This matches the 'explicit validation steps; feedback loops for error recovery' anchor; score 4's 'minor validation gaps' does not apply. No destructive/batch-operation cap applies to a planning skill.

Progressive Disclosure

The 'Required references' table (File / Read at / Holds) is exemplary one-level-deep navigation — better-signaled than the score-5 example — and all four `references/*.md` files exist and match their stated contents. However, two referenced paths (`../../assets/writing.md` and `<plugin root>/scripts/prose-lint.py`) do not resolve within the skill's bundle, so scored against the actual file listing plus referenced paths this is 'good structure ... minor organization gaps' rather than fully clean navigation.

Specificity

The description lists multiple concrete actions — "understand the problem, form a hypothesis, validate assumptions through real experiments and doc/code reads, and cross-check the proposed solution against product specs, architecture, and the existing codebase" — comprehensively covering the planning workflow with no vague filler. It clearly matches the 'multiple specific concrete actions; comprehensive coverage' anchor rather than the score-4 anchor, which tolerates coverage gaps.

Completeness

It explicitly answers both questions: the "what" is the full validate-then-plan pipeline, and the "when" is a concrete "Use when the user says ..." clause listing real trigger phrases plus a situational condition. This is a clear match for the 'clearly and explicitly answers both what AND when with concrete trigger phrases' anchor; the score-4 anchor's weaker 'when' does not apply.

Trigger Term Quality

Trigger phrases are natural and varied across registers ("/blueprint", "blueprint this", "plan this thoroughly", "deep plan", "I want to be sure before we build this", "a wrong direction would burn meaningful time, tokens, or compute"), but common variants like "design this", "spec this out", or "research before building" are absent. This lands between the 'good keyword coverage; a few natural terms missing' (4) anchor and comprehensive (5), and is noticeably above the midpoint of that gap.

Distinctiveness Conflict Risk

The closing line "Heavier and more deliberate than `/plan`; the goal is the global optimum, not a local one" explicitly differentiates it from the nearest competing skill. However, triggers like "plan this thoroughly" and "deep plan" could plausibly also invoke a lighter planning skill, so it is 'mostly distinct; minor overlap risk with closely related skills' rather than a fully conflict-free niche.