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aws-serverless

Routes serverless requests to a compute form factor and the skill that owns it. Applies first to Lambda, API Gateway, EventBridge, Step Functions and event-driven work while the compute, orchestration or integration choice is open — API backends, webhooks, jobs, cron, queue/stream consumers, durable workflows, event routing, Step Functions vs Durable Functions, and Pipes vs native event source mappings for queues and streams. Decides Event Functions on-demand vs Managed Instances, Web Functions, MicroVMs, EventBridge rules/Scheduler/Pipes/bus, HTTP vs REST API. Owns shared Lambda references (cold starts, SnapStart, concurrency, event sources, function URLs, throttling, troubleshooting). Defers to the specialized skill once a request commits to one form factor or service, or describes its defining feature, even unnamed (durable checkpointing and automatic step retries, Firecracker sandbox, managed instances, Node.js server). Not for EC2, ECS/EKS/Fargate or Amplify hosting.

77

Quality

97%

Does it follow best practices?

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SecuritybySnyk

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SKILL.md
Quality
Evals
Security

Quality

Content

92%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

A strong router skill body: an explicitly sequenced decision flow with a built-in revision loop, copy-paste-ready user questions and numeric thresholds, and clean one-level-deep progressive disclosure to ten real reference files. The only weakness is moderate redundancy — the ask-don't-tell rule and several thresholds are restated across Rules, Tier 3 and Tier 4, which inflates the token budget without adding decisions.

Suggestions

Consolidate the repeated Leaning/ask-the-question guidance: state it once in Rule 3 and have Tier 3 and the Tier 4 bullets reference it by tag instead of re-explaining it, saving several hundred tokens.

State each numeric threshold (duration ceilings, peak-to-mean ratio) in one place only — e.g. keep them in the Tier 1 constraints or the edge-cases reference — and cross-link rather than duplicating across Tier 1, Tier 3 and Tier 4.

DimensionReasoningScore

Conciseness

The body is dense decision guidance Claude does not already know (thresholds like 'peak-to-mean ratio below 2 within 5–10 minutes', '90 min on Managed Instances for async or ESM invocations', 'sessions up to 8 h') with no concept padding. Not score 5: the Leaning/ask-the-question pattern is restated in Rule 3, Tier 3 and multiple Tier 4 bullets, and duration/traffic thresholds repeat between Tier 1 constraints and Tier 4, so there is more than minor trimming opportunity.

4 / 5

Actionability

Fully actionable for an instruction-only skill: copy-paste user questions ('Does peak traffic stay below twice the average within any 5–10 minute window…?'), concrete commands ('aws lambda-web create-web-function'), a routing table with explicit do/don't-route columns, and a hand-off table mapping each decision to its owner. Not score 4: the specific examples cover the common cases with exact strings and numbers.

5 / 5

Workflow Clarity

A clearly sequenced multi-step flow (Step 0 entry point → Step 1 direct routes → Step 2 Tiers 1–4 → Steps 3–5 conditional) with an explicit feedback loop (Rule 4: 'New information → re-run the affected tier and update the recommendation'), a Decided/Leaning/Open/Unraised classification checklist, a 3–4 question budget, and a revise-before-answer ordering. Not score 4: validation checkpoints (classify before answering, confirm limits against shared references) are explicit, not implicit.

5 / 5

Progressive Disclosure

Headline decisions live in SKILL.md while details are pushed one level deep to ten real, verified reference files (compute-decision-edge-cases.md, orchestration.md, api-gateway.md, lambda.md, concurrency.md, event-sources.md, deployment.md, architecture.md, production.md, troubleshooting.md), each surfaced through a user-need→file table and inline links; implementation SOPs are delegated to separate skills. Not score 4: navigation is well-signaled in both directions with no nested references.

5 / 5

Total

19

/

20

Passed

Description

100%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

An excellent router description: concrete third-person actions, comprehensive natural trigger terms covering workloads and named AWS services, an explicit applies-first condition with de-trigger and exclusion clauses. Both what and when are answered at anchor-5 specificity with no fluff or over-claims.

DimensionReasoningScore

Specificity

The description lists multiple concrete actions in third-person voice ('Routes serverless requests to a compute form factor', 'Decides Event Functions on-demand vs Managed Instances, Web Functions, MicroVMs', 'Owns shared Lambda references (cold starts, SnapStart, concurrency…)', 'Defers to the specialized skill once a request commits'), covering routing, deciding, owning and deferring comprehensively. Not score 4: coverage of the router's actions is complete rather than having minor gaps.

5 / 5

Completeness

It explicitly answers both: what ('Routes serverless requests… Decides… Owns shared Lambda references… Defers') and when ('Applies first to Lambda, API Gateway, EventBridge, Step Functions and event-driven work while the compute, orchestration or integration choice is open'), with concrete de-trigger conditions ('once a request commits to one form factor or service') and exclusions ('Not for EC2, ECS/EKS/Fargate or Amplify hosting'). Not score 4: the when-clause is explicit and trigger-anchored, not merely present.

5 / 5

Trigger Term Quality

Natural phrases a user would actually say are comprehensively covered: 'API backends, webhooks, jobs, cron, queue/stream consumers, durable workflows, event routing, Step Functions vs Durable Functions, and Pipes vs native event source mappings', plus service names (Lambda, API Gateway, EventBridge) and operational keywords (cold starts, throttling). Not score 4: synonyms and workload-shape variations are included, not missing.

5 / 5

Distinctiveness Conflict Risk

A clear router niche with explicit boundary control: it names when it defers to specialized skills ('even unnamed (durable checkpointing…, Firecracker sandbox, managed instances, Node.js server)') and states what it is not for. Not score 4: the 'Not for…' clause and deferral triggers make overlap with adjacent skills minimal.

5 / 5

Total

20

/

20

Passed

Validation

100%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 16 / 16 Passed

Validation for skill structure

No warnings or errors.

Repository

aws/agent-toolkit-for-aws

Path

plugins/aws-core/skills/aws-serverless/SKILL.md

Reviewed

Table of Contents

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If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.