The body is lean and assumes Claude's competence—numbered workflow, explicit MUST constraints, and a one-level reference link—without padding or explaining concepts Claude already knows. Not level 2 because there is no unnecessary explanation to tighten.

Provides concrete decision criteria ("Recommend Parallel Change when old and new application versions or data interpretations must coexist" vs. "simpler forward-only migration when the change is additive, small, immediately safe") and named routing targets, which qualifies as concrete actionable guidance for an instruction-only skill. Absence of code is not penalized per the rubric's code-vs-instruction note.

A six-step sequenced workflow with explicit verification artifacts in step 4 (row-count expectations, duplicate detection, backfill monitoring, rollback behavior) and risk reporting in step 6, giving feedback/checkpoint loops appropriate for destructive database operations. Not level 2 because validation checkpoints are explicit rather than implicit.

SKILL.md is an overview that delegates detail to a real, one-level-deep reference (references/055-design-parallel-change.md, confirmed present), signaled in the Constraints, the workflow, and a dedicated Reference section with a markdown link. Organization is clear and navigation is easy.

Lists multiple concrete scenarios—"column renames, type or data reinterpretation, large-table backfills, relationship-table changes, enum/status transitions, timezone/default changes, and index or uniqueness changes"—plus the expand/migrate/contract sequencing, matching the comprehensive concrete-actions anchor rather than the partial level-2 anchor.

Explicitly answers both what (expand/migrate/contract sequencing across the listed scenarios) and when ("Use when a database schema or data-meaning change needs Parallel Change" and the "should trigger before framework-specific Flyway implementation guidance when deciding whether a migration needs a compatibility window" clause), with explicit triggers present.

Opens with a natural "Use when" trigger and includes terms users would say ("database schema," "column renames," "compatibility window," "backfills"); while some terms like "data reinterpretation" are specialized, coverage of natural triggers is good. Not level 2 because the breadth of user-facing terms exceeds 'some relevant keywords'.

Carves a clear niche (Parallel Change design for database migrations) with distinct triggers and an explicit hand-off boundary to framework-specific Flyway skills, making it unlikely to trigger for the wrong skill.