Conciseness

It does not pad with concepts Claude already knows (no basic explanations of what a product concept is), but it carries real redundancy: the 'Agent Invocation Guide' table (lines 265-284) largely restates the inline decision table (lines 188-207), and the dispatch-convention parenthetical is repeated verbatim ~4 times. This fits 'mostly efficient but could be tightened' rather than the every-token-earns-its-place anchor at 3.

Actionability

Provides concrete, copy-paste-ready guidance: exact agent names and modes (arn-spark-product-strategist, arn-spark-persona-architect 'discovery mode', arn-spark-market-researcher 'identification/plan|search|consolidate'), exact reference file paths, full AskUserQuestion prompts, and the output filename product-concept.md. As an instruction-only skill this matches the level-3 'fully executable / copy-paste ready' anchor.

Workflow Clarity

Clear Step 0 -> Step 5 sequence with explicit validation checkpoints (A-D plus a readiness check), feedback loops ('iterate until the user is satisfied'), a coverage-tracking checklist, and a dedicated error-handling section. No destructive/batch cap applies (document writes are guarded by an existence check), so it sits at the level-3 anchor rather than the implicit-checkpoint anchor at 2.

Progressive Disclosure

The four bundle reference files (discovery-questions.md, product-concept-template.md, persona-profile-template.md, competitive-landscape-template.md) all exist and are referenced one level deep with explicit 'Read ...' signals at the point of use; templates and the question bank are appropriately externalized from the orchestration body. Matches the level-3 anchor; not 2 because reference material is genuinely split out rather than inlined.

Specificity

Names concrete actions ('explore and structure a greenfield product idea through guided conversation') and a concrete deliverable ('Produces a product-concept.md document capturing the product vision, core experience, target users, trust model, platforms, and scope boundaries') with seven specific output components, matching the 'lists multiple specific concrete actions' anchor rather than the partial domain-only anchor at 2.

Completeness

Explicitly answers both WHAT (structured guided conversation producing a product-concept.md with named fields) and WHEN ('This skill should be used when the user says...'), matching the level-3 anchor; not 2 because the 'when' is explicit, not merely implied.

Trigger Term Quality

Provides thirteen natural phrases a user would actually say ('discover', 'product discovery', 'arn discover', 'help me define this product', 'what should I build', 'brainstorm this product', 'starting from scratch'), exceeding the coverage of the level-3 anchor example.

Distinctiveness Conflict Risk

The product-concept framing and 'arn discover' trigger carve a niche, but broad catch-all phrases ('what should I build', 'starting from scratch', 'brainstorm this product', 'shape this idea') could overlap with generic ideation/brainstorming skills, matching the 'somewhat specific but could still overlap' anchor rather than the clearly-conflict-free anchor at 3.