Status: Accepted
Date: 2026-06-30

Context

The D1 (Knowledge Delta) scorer only measured content volume and topical coverage, missing whether the skill provides concrete demonstrations. A skill can list facts without showing how to apply them, inflating its D1 score without delivering actionable knowledge.

Decision

Add a “Demonstration Concreteness” sub-criterion (3 pts) to D1 that detects concrete demonstrations via three signals: code fences, arrow notation (→), and explicit output sections. Reduce d1BaseScore from 15 to 12 to accommodate the new sub-points without changing the D1 max of 20.

Consequences

• D1 now rewards actionable demonstrations, not just content breadth
• Three-signal heuristic is simple and deterministic
• Existing high-scoring skills may regrade slightly lower on pure breadth without demos
• Implemented in the same refactor as the dimension registry pattern (ADR-006)