AWS Cost Analysis
Query AWS Cost Explorer data to break down spending by service, identify trends, detect anomalies, and recommend cost optimization actions.
Instructions
Phase 1: Cost Breakdown
- •Fetch cost data using the AWS agent's Cost Explorer tools:
- •Total spend for the requested period (default: last 30 days)
- •Breakdown by AWS service (EC2, EKS, S3, RDS, Lambda, etc.)
- •Breakdown by account (if multi-account)
- •Daily/weekly cost trends
- •Calculate key metrics:
- •Month-over-month change (absolute and percentage)
- •Top 5 most expensive services
- •Top 5 fastest-growing services (by percentage increase)
Phase 2: Anomaly Detection
- •Identify cost anomalies:
- •Services with >20% cost increase vs. previous period
- •Sudden spikes in daily spend
- •New services that appeared this period
- •Unused resources still incurring charges
- •Flag potential waste:
- •Idle EC2 instances (low CPU utilization)
- •Unattached EBS volumes
- •Old snapshots and AMIs
- •Underutilized RDS instances
- •NAT Gateway data transfer costs
Phase 3: Optimization Recommendations
Provide actionable recommendations with estimated savings:
- •Reserved Instances or Savings Plans opportunities
- •Right-sizing overprovisioned resources
- •Storage tier optimization (S3 lifecycle policies)
- •Spot Instance candidates for non-critical workloads
- •Cleanup of orphaned resources
Output Format
markdown
## AWS Cost Analysis Report **Period**: Feb 1 - Feb 9, 2026 | **Total Spend**: $24,567.89 ### Cost Trend | Week | Spend | Change | |------|-------|--------| | Jan 27 - Feb 2 | $5,890 | baseline | | Feb 3 - Feb 9 | $6,234 | +5.8% | ### Top 5 Services by Cost | Service | Cost | % of Total | MoM Change | |---------|------|------------|------------| | Amazon EKS | $8,234 | 33.5% | +12% | | Amazon EC2 | $6,789 | 27.6% | -3% | | Amazon S3 | $3,456 | 14.1% | +2% | | Amazon RDS | $2,345 | 9.5% | +0% | | AWS Lambda | $1,234 | 5.0% | +45% | ### Anomalies Detected 1. **Lambda costs up 45%** - New function `data-pipeline-processor` deployed Feb 3 2. **EKS costs up 12%** - Node group scaled from 5 to 8 nodes ### Optimization Opportunities | Recommendation | Estimated Monthly Savings | |---------------|--------------------------| | Right-size 3 oversized EC2 instances | $450/mo | | Purchase EKS Savings Plan | $1,200/mo | | Delete 12 unattached EBS volumes | $180/mo | | **Total Potential Savings** | **$1,830/mo** |
Examples
- •"Show me the AWS cost breakdown for the last month"
- •"What are our top 5 most expensive AWS services?"
- •"Are there any cost anomalies this month?"
- •"How can we reduce our AWS spend?"
- •"Compare this month's AWS costs to last month"
Guidelines
- •Default to last 30 days if no time period is specified
- •Always show both absolute costs and percentage of total
- •Include month-over-month comparison for context
- •Round costs to 2 decimal places for totals, whole dollars for individual services
- •When costs exceed expectations, investigate the root cause before recommending action
- •Be specific in optimization recommendations (name the resource, not just the category)
- •Distinguish between one-time spikes and sustained cost increases