Claude Skills + MCP Server: Create Consistent AWS Cost Reports in Minutes

Source: Dev.to

Introduction

This article is useful for FinOps engineers who want to automate their monthly cost‑reporting workflow. FinOps focuses on managing cloud costs efficiently, but creating consistent executive reports every month is time‑consuming and error‑prone. Most companies spend heavily on cloud infrastructure, and CTOs need clear, standardized reports to track spending trends. A system that generates professional cost reports with the same structure each month eliminates ad‑hoc prompts that vary in quality.

In this guide you’ll learn how to build a Claude Skill that combines MCP Server with AWS Cost Explorer to create deterministic, executive‑ready cost reports in just a few minutes. Once configured, you’ll never need to craft complex prompts again.

What is MCP Server?

MCP (Model Context Protocol) Server is a technology that lets AI assistants like Claude connect directly to external tools and data sources. It acts as a bridge between Claude and your cloud infrastructure.

In this context, the AWS Cost Explorer MCP Server enables Claude to:

• Make API calls to AWS Cost Explorer
• Fetch actual spending data in real time
• Analyze usage patterns
• Retrieve detailed cost breakdowns

Without MCP, you would have to manually export cost data from AWS, format it, and paste it into Claude. With MCP, Claude accesses the data automatically.

What Are Claude Skills?

Claude Skills are reusable expert templates. Instead of explaining your requirements each time, you create a skill file that contains all instructions, preferences, and guidelines. Claude then follows this “playbook” perfectly whenever you invoke it.

For FinOps reporting, this means:

• Identical professional structure every month
• Consistent analysis framework
• No forgotten requirements
• Executive‑ready format guaranteed

Prerequisites for Claude Skill Creation

Before creating the skill, set up the necessary tools and permissions:

• Install Claude Desktop – download from claude.ai/download
• Add AWS Cost Explorer MCP Server – configure the MCP server in Claude Desktop settings by adding it to your configuration file
• Configure AWS IAM Permissions – create an IAM user with Cost Explorer read permissions and configure the credentials

Detailed setup instructions for the MCP server and IAM configuration are available in the AWS Cost Explorer MCP Server documentation.

Creating an AWS Cost Report Skill

Step‑by‑step workflow

1. Ask Claude: “Help me create a skill for generating monthly AWS cost reports.”
2. Claude will ask clarifying questions about:
   • Data sources and tools you use
   • Infrastructure organization (tags, environments)
   • Expected report structure for executives
   • Desired level of detail and visualizations
   • Required analysis and recommendations
3. Based on your answers, Claude automatically generates a skill file containing detailed, structured instructions. The file defines how Claude should fetch data, analyze it, generate visualizations, and format the final report.
4. Save the generated skill file in Claude Desktop.
5. To use the skill, simply type a trigger phrase, e.g.:

Use the AWS Cost CEO Report skill to compare November and December 2025 costs.

Claude will follow the instructions in the skill file and deliver a consistent, professional report every time.

Example Claude Skill reference file

# AWS Cost CEO Report Skill - Quick Reference

## 🚀 Quick Start
AWS cost report for the CEO - September vs October 2025

## ✅ Prerequisites Checklist
- [ ] All Cost Explorer MCP servers are started
- [ ] You have cost data for the months you want to compare

## 🎯 Trigger Phrases
| What to Say                         | What It Does                         |
|-------------------------------------|--------------------------------------|
| "AWS cost report for the CEO"      | Generates full report for all accounts |
| "Compare September vs October 2025"| Month‑to‑month comparison             |
| "Production account only"           | Limits to single account             |
| "We implemented VPC endpoints..."   | Includes savings actions analysis    |

## 📊 Report Includes
- Executive summary with key metrics  
- Visual charts and graphs  
- Per‑account breakdowns  
- Cost driver analysis  
- Optimization recommendations  
- PDF export capability  

## 🎨 Report Filters
- Shows only services with > $50/month spend  
- Analyzes services with > 10 % change **or** > $100 change  
- Focuses on top cost drivers  

## 💡 Pro Tips
1. **Monthly Cadence** – Generate reports at month‑end.  
2. **Include Context** – Mention infrastructure changes or savings actions.  
3. **Review Trends** – Look for unexpected cost increases.  
4. **Act on Recommendations** – Follow the optimization section.  
5. **Export PDF** – Use browser print function to save as PDF.  

## 🚨 Common Issues
| Issue                     | Solution                                   |
|---------------------------|--------------------------------------------|
| MCP servers not accessible| Start Docker Desktop and MCP containers    |
| Invalid month format      | Use "September 2025" not "9/2025"          |
| No data returned          | Check dates aren't in the future           |

## 📈 Cost Optimization Areas Analyzed
- EC2 instance rightsizing  
- NAT Gateway optimization (VPC endpoints)  
- Data transfer costs  
- Idle resources  
- Over‑provisioned infrastructure  
- Development environment scheduling  
- Storage lifecycle policies  
- Reserved Instance opportunities  

## 🎓 Example Requests
**Basic Report:**  
`Generate AWS cost report for the CEO comparing September vs October 2025`

**With Savings Context:**  
`AWS cost report for September vs October 2025. Actions taken: Implemented VPC endpoints, migrated to Graviton instances, enabled S3 Intelligent Tiering.`

## 📦 Skill Components
- Main workflow instructions (`SKILL.md`)  
- MCP usage patterns (`references/mcp-usage.md`)  
- Report structure guide (`references/report-structure.md`)  
- HTML template reference (`scripts/generate_report.py`)  

## 🔍 Analysis Depth
- **Level 1:** Service‑level cost comparison  
- **Level 2:** Usage‑type breakdown (instance types, hours)  
- **Level 3:** Root cause identification  
- **Level 4:** Contextual analysis with recommendations  

## 💰 Cost Leak Detection
The skill automatically flags:
- Unexpected spikes > 20 %  
- High data transfer costs  
- NAT Gateway optimization opportunities  
- Idle resources  
- Over‑provisioned instances  
- 24/7 dev/test environments  
- Legacy unused resources  

## 📄 Export to PDF
1. Open artifact in a new window  
2. Press **Ctrl+P** (or **Cmd+P** on Mac)  
3. Select “Save as PDF”  
4. Adjust settings if needed  
5. Save and share!  

Benefits for FinOps Teams

• Reproducibility: Same report quality every month
• Scalability: Easy to generate reports for multiple accounts/regions
• Compliance: Standardized format satisfies audit requirements
• Onboarding: New team members can generate reports without extensive training
• Evolution: Update the skill once to improve all future reports

Conclusion

MCP Server combined with Claude Skills transforms FinOps reporting from a day‑long manual process into a few‑minute automated workflow. You get the speed of AI‑powered analysis with the consistency and professionalism that executive leadership demands.