Conciseness

The Quick Start and gate are tight, but roughly 350 of the 428 lines re-teach patterns Claude already knows verbatim — expand-contract, dual-write, CDC, strangler fig, canary, blue-green, circuit breakers, generic risk matrices, and filler like "Use cloud migration tools and services." This is noticeably-to-severely padded; the genuinely skill-specific content is a small fraction of the token budget.

Actionability

The Quick Start gives concrete chained commands (migration_plan.json → compatibility.json → rollback runbook) with named output fields, which is strong — but the referenced scripts/migration_planner.py, compatibility_checker.py, and rollback_generator.py do not exist in the bundle, so the commands cannot actually run. The inline Python (MigrationCircuitBreaker references a never-initialized self.new_service) and the Terraform/CI snippets are illustrative sketches rather than executable code, matching the 3 anchor.

Workflow Clarity

The Quick Start sequence (plan → check compatibility → generate rollback) is clearly ordered, outputs chain explicitly, and the Gate section defines validation criteria (exit 0 / owner sign-off, runbook per phase) plus a re-run instruction after schema revision — genuine feedback loops. It falls short of the 5 anchor because the broader pre/during/post checklists and pattern guidance are not integrated into that workflow, leaving minor validation gaps.

Progressive Disclosure

The body references scripts/, assets/, and expected_outputs/ files that are absent from the bundle (broken navigation), while ~350 lines of pattern reference material that clearly belongs in separate reference files are inlined in SKILL.md. This matches the 2 anchor ('content that clearly belongs in separate files is inlined'); it is above the 1 anchor only because section headers and a real Quick Start provide some structure.

Specificity

The description names several concrete capabilities — "Zero-downtime migration planning, compatibility validation, and rollback strategy generation" — plus the domain ("system, database, and infrastructure migrations") and tooling. It stops short of the 5 anchor's comprehensive action list (e.g., schema evolution analysis and API versioning detection covered in the body are absent here).

Completeness

Both halves are explicit: the "what" is "Zero-downtime migration planning, compatibility validation, and rollback strategy generation" and the "when" is the concrete trigger clause "Use when planning a database migration, infrastructure cutover, system replacement, or any high-risk transition that needs explicit rollback paths." This matches the 5 anchor directly; the 4 anchor's softer 'when could be more explicit' does not apply.

Trigger Term Quality

"database migration", "infrastructure cutover", "system replacement", "high-risk transition", and "rollback paths" are phrases a user would plausibly say. A few natural variants are missing ("schema migration", "data migration", "moving to a new database/cloud"), keeping it below the 5 anchor's synonym-complete coverage; it is clearly above the 3 anchor's "some relevant keywords".

Distinctiveness Conflict Risk

The zero-downtime/rollback-strategy framing carves a fairly distinct niche with concrete triggers, but it could still overlap with generic database-administration or deployment/CI skills. Minor overlap risk with closely related skills fits the 4 anchor; the 5 anchor's 'clear niche with minimal conflict risk' is slightly undercut by how broad "any high-risk transition" is.