Conciseness

The body is dense and mostly non-padding — DocumentDB-specific facts like "DocumentDB uses left-prefix matching on compound indexes" and "retryWrites=false" earn their tokens — but several sections are duplicated: slow-query fact 5 ("Verify with `explain()` after the index is created") restates the second half of fact 1, the "Resource tagging" section repeats the `--tags` flags already shown inline in both create commands, the Elastic Clusters warning appears in both the Out-of-scope note and the architecture primer, and the Cost Estimator link and documentdb-pm@amazon.com email each appear twice. This fits "mostly efficient but includes some unnecessary explanation or could be tightened"; it is not 4 because the duplication is recurring across several sections rather than a couple of minor instances.

Actionability

Guidance is fully executable: copy-paste-ready `aws docdb create-db-cluster` / `create-db-instance` commands with exact flags, DMS endpoint settings (`--ssl-mode verify-full` with `--certificate-arn`), connection-string parameters (`tls=true`, `replicaSet=rs0`, `retryWrites=false`), a runnable dependency check, and even a scripted refusal template. It matches the copy-paste-ready anchor covering the common cases; no pseudocode or missing key details.

Workflow Clarity

Multi-step processes are clearly sequenced (Verify Dependencies -> Classify and Route -> Execute -> surface Critical Facts, with a Decision Guide table and stated pipeline order) and validation checkpoints with feedback loops are explicit throughout: "re-run `explain()` to confirm `IXSCAN`", "poll `describe-connections` until both return `successful`", "watch `CDCLatencySource`... Cut over only when lag is near zero". Destructive operations have a mandatory pause-and-confirm gate, so the destructive-operations cap does not apply. This matches the level-5 anchor with error-recovery loops; it is not 4 because checkpoints are explicit rather than implied.

Progressive Disclosure

The body is an overview with a well-signaled decision table routing to nine real, one-level-deep reference files (all verified present: connection.md, connection-drivers.md, schema-advisor.md, compatibility.md, migration.md, performance.md, well-architected.md, upgrade.md, troubleshooting.md) plus scripts/wa_review.py, and the referenced "## Workflow" sections exist in those files. It is not 5 because the ~210-line body inlines substantial material — full cluster-creation commands, the five Critical Facts lists, and the tagging subsection — that could live in the references; placement is defensible as always-load content, which puts it at "good structure; most content appropriately placed; minor organization gaps".

Specificity

Lists ten concrete capabilities in third person — "serverless-on-8.0 cluster setup, TLS/VPC/driver config, flexible-schema and vector-search data modeling, MongoDB compatibility assessment, DMS-based migration, slow-query diagnosis, major version upgrades (4.0->5.0->8.0), Well-Architected reviews (41-check wa_review.py), cost estimation, and security hardening" — with version specifics and tool names, matching the comprehensive-coverage anchor. It is not a 4 because there are no gaps in the enumerated action coverage relative to the skill's scope.

Completeness

Explicitly answers "what" ("Manages Amazon DocumentDB end-to-end — ..." with an itemized capability list) and "when" ("Retrieve for every DocumentDB question and when the user asks to set up or migrate MongoDB to AWS", reinforced by the Triggers list), which is the clear-and-explicit-both pattern of the level-5 anchor. It exceeds level 4 because the 'when' clause is specific and paired with concrete trigger phrases rather than generic.

Trigger Term Quality

An explicit "Triggers:" list covers ~24 natural user phrases and technical synonyms — "JSON document store", "document database", "MongoDB on AWS", "Lambda cannot connect", "TLS handshake", "VPC port 27017", "COLLSCAN", "DMS migration", "CDC cutover", "$vectorSearch", "RAG", "Global Clusters", "cost sizing", "health check", "production-readiness" — spanning both lay phrasings and expert jargon. Coverage includes variations and synonyms, matching the level-5 anchor; nothing common is missing.

Distinctiveness Conflict Risk

The DocumentDB niche is clear and most triggers ("VPC port 27017", "CDC cutover", "retryWrites") are unambiguous, but a few terms — "RAG", "cost sizing", "audit", "health check", "production-readiness" — are generic enough to overlap with other AWS database or vector-search skills (the skill itself lists related skills like amazon-aurora and amazon-neptune). This matches "mostly distinct; minor overlap risk with closely related skills"; it is not 5 because those generic trigger terms create real, if minor, cross-trigger risk.