aws-expert

name	aws-expert
description	AWS expert guardrails — IAM least-privilege, data boundaries, cost controls, residency, and official-source validation. Trigger when designing or reviewing any AWS workload, especially agents, LLMs (Bedrock), or multi-account systems.

AWS Expert

The Well-Architected pillars are the floor, not the ceiling. On AWS, IAM and cost are where agent workloads blow up first.

This skill enforces the discipline that makes AWS workloads production-safe: identity, data boundaries, cost controls, and regional residency. It is not an AWS feature tour — it is a checklist of the things that cause incidents and compliance failures when skipped.

When to use

• Designing any AWS infrastructure (new or modified)
• Before deploying agents or LLM workloads to AWS (Bedrock, AgentCore, Strands)
• When reviewing a CloudFormation/CDK/Terraform plan for an AWS workload
• When a system spans multiple accounts, touches regulated data, or crosses regions

Procedure

1. Identity and IAM — verify least-privilege for every role and human principal:

   • No wildcard Action: "*" with Resource: "*" on any role. Managed policies scoped to the specific function.
   • Roles over IAM users; IRSA for EKS, instance profiles for EC2. No long-lived access keys in workloads.
   • SCPs at the OU level deny sensitive services by default; permission boundaries on delegated admin.
   • CloudTrail enabled on all management and data-plane events, shipped to a log-archive account.

2. Data boundaries — for every data store in the design:

   • What data classification does it hold (public / internal / confidential / regulated)?
   • S3 Block Public Access at account level; bucket policies explicit; KMS CMK where required.
   • Cross-account sharing only via explicit resource policy with external ID.
   • Tenant boundaries enforced at the data layer, not just the application layer.

3. Data residency — for each resource:

   • Region allow-list enforced by SCP, not convention.
   • For Bedrock / LLM calls: regional endpoints; check cross-region inference profiles where residency matters.

4. Cost controls — for every LLM, compute, or storage resource:

   • AWS Budgets alerts at 50%, 75%, 90%, 100%.
   • Bedrock invocation quotas/caps and rate limits set; unbounded agent loops are unbounded spend.
   • Autoscaling maximums set; Savings Plans / Spot evaluated where appropriate.

5. Network and egress — confirm:

   • PrivateLink / VPC endpoints used where public endpoints are avoidable.
   • Security groups default-deny with explicit allow rules; egress costed for cross-region and internet traffic.

6. Observability — confirm:

   • CloudWatch dashboards and alarms on error rate, latency, and cost thresholds.
   • X-Ray tracing on agent/LLM call paths.
   • CloudTrail as audit evidence — enabled before go-live, not after an incident.

7. Run the Adversarial Gate — common AWS failure modes: wildcard IAM, public S3, uncapped Bedrock spend, missing CloudTrail data events, global endpoints on residency-sensitive data.

Official sources — validate before you assert

• Documentation: docs.aws.amazon.com · Well-Architected: docs.aws.amazon.com/wellarchitected
• Live docs via MCP (verify currency before pinning): the official awslabs/mcp monorepo includes the AWS Documentation MCP Server — fetch current docs instead of relying on memory.
• GitHub, foundations: github.com/awslabs · github.com/aws-ia · github.com/aws-samples
• GitHub, agent examples: github.com/strands-agents/sdk-python · Bedrock agent samples under github.com/aws-samples
• Rule: every service/API claim cites an official doc. Quotas, prices, and model IDs are dated facts — stale until re-verified against the source.

Outputs

• AWS guardrail checklist (pass/fail per item)
• IAM matrix: principal | role | scope | justification
• Data classification and boundary map
• Budget alert confirmation
• Open findings for human review

Guardrails

• No wildcard actions on wildcard resources. Ever.
• Residency is a constraint, not a preference. Enforce with SCPs, not conventions.
• Budget alerts are not optional. An unmonitored LLM workload will produce a surprise invoice.
• CloudTrail is evidence. Enable it before go-live, not after an incident.