aws-cloudformation-ec2
AWS CloudFormation patterns for EC2 instances, Security Groups, IAM roles, and load balancers. Use when creating EC2 instances, SPOT instances, Security Groups, IAM roles for EC2, Application Load Balancers (ALB), Target Groups, and implementing template structure with Parameters, Outputs, Mappings, Conditions, and cross-stack references.
Install with Tessl CLI
npx tessl i github:giuseppe-trisciuoglio/developer-kit --skill aws-cloudformation-ec279
Does it follow best practices?
If you maintain this skill, you can automatically optimize it using the tessl CLI to improve its score:
npx tessl skill review --optimize ./path/to/skillValidation for skill structure
Discovery
100%Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.
This is an excellent skill description that clearly defines its scope (AWS CloudFormation patterns), lists specific capabilities (EC2, Security Groups, IAM roles, ALB, template structures), and provides explicit trigger guidance with a comprehensive 'Use when...' clause. The description uses proper third-person voice and includes both technical terms and natural language variations users would employ.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions and resources: EC2 instances, SPOT instances, Security Groups, IAM roles, ALB, Target Groups, plus template structure elements like Parameters, Outputs, Mappings, Conditions, and cross-stack references. | 3 / 3 |
Completeness | Clearly answers both what (AWS CloudFormation patterns for specific resources and template structures) and when (explicit 'Use when...' clause listing specific trigger scenarios like creating EC2 instances, Security Groups, IAM roles, ALBs). | 3 / 3 |
Trigger Term Quality | Excellent coverage of natural terms users would say: 'EC2 instances', 'SPOT instances', 'Security Groups', 'IAM roles', 'ALB', 'Application Load Balancers', 'Target Groups', 'CloudFormation', 'Parameters', 'Outputs', 'cross-stack references'. | 3 / 3 |
Distinctiveness Conflict Risk | Very clear niche focused specifically on AWS CloudFormation with EC2-related resources. The combination of CloudFormation + specific AWS services (EC2, ALB, IAM for EC2) creates distinct triggers unlikely to conflict with general AWS or Terraform skills. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
64%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This skill provides excellent actionable CloudFormation templates with comprehensive coverage of EC2 infrastructure patterns. However, it suffers from verbosity—explaining concepts Claude knows and including many similar variations inline rather than referencing separate files. The validation and deployment workflow guidance exists but isn't integrated into a clear step-by-step process.
Suggestions
Move the 'Complete Example' and detailed ALB/SPOT variations to EXAMPLES.md, keeping only 2-3 core patterns in the main skill
Remove explanatory sections like 'Template Sections Overview' and 'Format Version' that explain basic CloudFormation concepts Claude already knows
Add an explicit deployment workflow section at the top: 1) Write template → 2) Validate with cfn-lint → 3) Create change set → 4) Review changes → 5) Execute
Consolidate the Best Practices section—Stack Policies, Termination Protection, Drift Detection, and Change Sets could be a separate OPERATIONS.md file
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is comprehensive but overly verbose for Claude's capabilities. Many sections explain basic CloudFormation concepts (template sections, format version) that Claude already knows, and the extensive repetition of similar patterns (multiple ALB examples, multiple security group examples) could be significantly condensed. | 2 / 3 |
Actionability | Excellent actionability with fully executable YAML templates throughout. Every pattern includes complete, copy-paste ready CloudFormation code with proper syntax, realistic parameter values, and working resource configurations. | 3 / 3 |
Workflow Clarity | While validation commands are provided (cfn-lint, validate-template), the skill lacks explicit validation checkpoints integrated into deployment workflows. The drift detection and change set sections are good but appear late and disconnected from the main deployment flow. Missing explicit 'validate before deploy' sequences. | 2 / 3 |
Progressive Disclosure | References to EXAMPLES.md and REFERENCE.md are mentioned but the main document is monolithic (~1200 lines). Content like the complete example stack, all the ALB variations, and detailed best practices sections could be split into separate files with clear navigation from a leaner overview. | 2 / 3 |
Total | 9 / 12 Passed |
Validation
62%Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.
Validation — 10 / 16 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
skill_md_line_count | SKILL.md is long (1811 lines); consider splitting into references/ and linking | Warning |
allowed_tools_field | 'allowed-tools' contains unusual tool name(s) | Warning |
metadata_version | 'metadata' field is not a dictionary | Warning |
license_field | 'license' field is missing | Warning |
frontmatter_unknown_keys | Unknown frontmatter key(s) found; consider removing or moving to metadata | Warning |
body_steps | No step-by-step structure detected (no ordered list); consider adding a simple workflow | Warning |
Total | 10 / 16 Passed | |
- Reviewed
Table of Contents
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