aws-cloudformation-s3
AWS CloudFormation patterns for Amazon S3. Use when creating S3 buckets, policies, versioning, lifecycle rules, 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-s383
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 a well-crafted skill description that excels across all dimensions. It clearly identifies the specific domain (CloudFormation for S3), lists concrete capabilities, includes an explicit 'Use when' clause with natural trigger terms, and occupies a distinct niche that minimizes conflict risk with other skills.
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: 'creating S3 buckets, policies, versioning, lifecycle rules' and template elements like 'Parameters, Outputs, Mappings, Conditions, and cross-stack references'. Uses third person voice appropriately. | 3 / 3 |
Completeness | Clearly answers both what ('AWS CloudFormation patterns for Amazon S3') and when ('Use when creating S3 buckets, policies, versioning, lifecycle rules...'). Has explicit 'Use when' clause with specific trigger scenarios. | 3 / 3 |
Trigger Term Quality | Includes natural keywords users would say: 'AWS', 'CloudFormation', 'S3', 'buckets', 'policies', 'versioning', 'lifecycle rules', 'Parameters', 'Outputs', 'cross-stack references'. Good coverage of both service names and specific features. | 3 / 3 |
Distinctiveness Conflict Risk | Very specific niche combining CloudFormation + S3 specifically. The combination of infrastructure-as-code tool (CloudFormation) with a specific AWS service (S3) creates a clear, distinct scope unlikely to conflict with general AWS skills or other IaC tools. | 3 / 3 |
Total | 12 / 12 Passed |
Implementation
72%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a comprehensive CloudFormation S3 skill with excellent actionable code examples and good progressive disclosure. The main weaknesses are verbosity (explaining concepts Claude knows, like what template sections do) and missing explicit validation workflows for stack deployments. The content would benefit from trimming explanatory prose and adding a clear pre-deployment validation checklist.
Suggestions
Remove or significantly condense the 'When to Use' section and explanatory text about template sections - Claude already understands these concepts
Add an explicit validation workflow at the beginning: validate template syntax → create change set → review → execute, with error handling for each step
Consolidate the 'Template Structure' section into a brief reference table rather than verbose explanations of each section's purpose
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is comprehensive but includes some unnecessary verbosity, such as the 'When to Use' section that largely restates what Claude would infer, and explanatory text like 'Template Sections Overview' that describes concepts Claude already knows. The content could be tightened significantly. | 2 / 3 |
Actionability | Excellent actionability with fully executable YAML templates, complete bash scripts, and Python code examples. All code is copy-paste ready with proper syntax and realistic configurations. | 3 / 3 |
Workflow Clarity | While individual scripts have clear steps, the overall skill lacks explicit validation checkpoints for CloudFormation deployments. The change set section shows good workflow patterns, but there's no clear 'validate template before deploy' step or error recovery guidance for failed stack operations. | 2 / 3 |
Progressive Disclosure | Good structure with clear sections progressing from Quick Start to advanced topics. References to external files (reference.md, examples.md) are well-signaled at the end, and content is appropriately organized with logical groupings. | 3 / 3 |
Total | 10 / 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 (1314 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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