AWS Idle Resources

AWS Idle Resources Skill

Detect unused and idle AWS resources with anti-hallucination guardrails and cost waste estimation.

Relationship to other AWS skills:

• aws-idle-resources/ -> "What is wasting money" (idle detection rules, cost estimation, protection tag checks)
• aws/ -> "How to execute" (parallel patterns, filtering hierarchy, pagination)
• aws-pricing/ -> "How much things cost" (on-demand pricing via get_aws_cost)
• aws-billing/ -> "Current spend" (billing context, discount detection)

CRITICAL: Idle Resource Detection Rules (Anti-Hallucination)

These rules are MANDATORY when detecting idle resources. Violating them produces recommendations that can cause data loss or outages.

Rule 1: "Available" EBS != Always Deletable

Detached EBS volumes in "available" state may be intentional (warm standby, manual backups, data archives). Report but NEVER auto-recommend deletion without user context.

WRONG:  "vol-abc is detached, delete it"
CORRECT: "vol-abc is detached (available), candidate for review. Created 2025-06-15, 100GB gp3, est. $8/mo"

Rule 2: Stopped EC2 Still Incurs EBS + EIP Costs

When an EC2 instance is stopped, compute charges stop but attached EBS volumes and associated Elastic IPs continue to incur charges.

MANDATORY: Report the ongoing cost of stopped instances, not just the compute savings.

WRONG:  "i-abc is stopped, no cost"
CORRECT: "i-abc is stopped since 2025-12-01. Ongoing cost: 2x EBS volumes ($24/mo) + 1 EIP ($3.60/mo) = $27.60/mo"

Rule 3: EIP Cost: $0.005/hr ($3.60/mo) Per Public IPv4

Since February 2024, AWS charges $0.005/hr for ALL public IPv4 addresses, including EIPs attached to running instances. An unassociated EIP is pure waste because it costs money AND provides zero value.

WRONG:  "EIP attached to running instance is free"
CORRECT: "All EIPs cost $3.60/mo. EIP eipalloc-abc is unassociated -- pure waste at $3.60/mo"
CORRECT: "EIP eipalloc-def is attached to running i-123 -- cost exists but provides value"

Rule 4: NAT Gateway: $0.045/hr ($32.40/mo) Minimum

NAT Gateways have a fixed hourly charge regardless of traffic, plus $0.045/GB data processed. Even idle NAT Gateways cost $32+/mo.

WRONG:  "NAT Gateway has low traffic, minimal cost"
CORRECT: "NAT Gateway nat-abc has < 10 active connections/day avg. Fixed cost: $32.40/mo + data processing charges"

Rule 5: Snapshot Cost: $0.05/GB/mo (Standard)

Old snapshots accumulate silently. 1TB of old snapshots = $50/mo. However, some snapshots back AMIs and are required.

MANDATORY: Cross-reference with describe-images --owners self to exclude snapshots that back active AMIs before flagging.

WRONG:  "snap-abc is 90 days old, delete it"
CORRECT: "snap-abc is 90 days old, 200GB, est. $10/mo. NOT backing any AMI. Candidate for review."
CORRECT: "snap-def is 120 days old, 500GB. BACKS AMI ami-xyz -- skipped (required by AMI)."

Rule 6: Never Recommend Deletion -- Only Flag

Always phrase results as "candidate for review" not "should be deleted". Resources may be intentionally idle (DR, staging, warm standby).

WRONG:  "Delete these 5 volumes to save $87/mo"
CORRECT: "5 detached volumes identified as candidates for review. Estimated waste: $87/mo if all are unnecessary."

Rule 7: Check Protection Tags Before Flagging

Look for tags like do-not-delete, keep, protected, backup, DoNotDelete. If found, mark as "protected -- skipped" in the output.

WRONG:  "vol-abc (tagged keep) is idle, candidate for deletion"
CORRECT: "vol-abc: PROTECTED (tag: keep) -- skipped"

Mandatory Pre-Detection Checklist

Before writing ANY idle resource analysis, verify ALL of the following:

• Region context established (current or specified via --region)
• Protection tags checked before flagging any resource (see Rule 7)
• Cost estimates use current on-demand pricing (see pricing table below)
• Results clearly state "candidates for review" not "should be deleted" (see Rule 6)
• Each resource shows estimated monthly waste
• All costs include currency unit (USD)
• Snapshot-AMI cross-reference performed (see Rule 5)
• Parallel execution used for all AWS API calls (see aws/SKILL.md)

Idle Resources Script (get_idle_resources_aws.sh)

DO NOT read or modify the script file. Only source and call the functions.

SETUP (at the start of your script):

source ./_skills/connections/aws/aws-idle-resources/scripts/get_idle_resources_aws.sh

All functions enforce anti-hallucination rules: protection tag checks, cost estimation, "candidate for review" language, TOON output format.

FUNCTION REFERENCE:

RECOMMENDED WORKFLOW (every idle resource analysis):

1. Run aws_idle_summary for a unified view of all idle resource types with total waste estimate
2. For deeper analysis of a specific category, run the individual function
3. Always review "PROTECTED" items separately -- they were intentionally tagged

Examples:

source ./_skills/connections/aws/aws-idle-resources/scripts/get_idle_resources_aws.sh

# Full idle resource scan (default region)
aws_idle_summary

# Full scan in specific region
aws_idle_summary --days 30 --region us-west-2

# Detached EBS volumes only
aws_idle_ebs

# Idle load balancers (7-day window)
aws_idle_elb --days 7

# Unused Elastic IPs
aws_idle_eip

# Long-stopped EC2 instances (60-day threshold)
aws_idle_ec2_stopped --days 60

# Idle NAT Gateways
aws_idle_natgw --days 14

# Old snapshots (120-day threshold)
aws_idle_snapshots --days 120

# Unused network interfaces
aws_idle_eni --region eu-west-1

Resource Cost Reference

Approximate monthly costs in USD. Use to validate waste estimates.

For resources not listed above, use get_aws_cost from the aws-pricing/ skill.

Common Errors

Output Format

Present results as a structured report:

Aws Idle Resources Report
═════════════════════════
Resources discovered: [count]

Resource       Status    Key Metric    Issues
──────────────────────────────────────────────
[name]         [ok/warn] [value]       [findings]

Summary: [total] resources | [ok] healthy | [warn] warnings | [crit] critical
Action Items: [list of prioritized findings]

Target ≤50 lines of output. Use tables for multi-resource comparisons.

Counter-Rationalizations