auditing-aws-s3-bucket-permissions
Systematically audit AWS S3 bucket permissions to identify publicly accessible buckets, overly permissive ACLs, misconfigured bucket policies, and missing encryption settings using AWS CLI, S3audit, and Prowler to enforce least-privilege data access controls.
83
80%
Does it follow best practices?
Impact
Pending
No eval scenarios have been run
Passed
No known issues
Optimize this skill with Tessl
npx tessl skill review --optimize ./skills/auditing-aws-s3-bucket-permissions/SKILL.mdQuality
Discovery
82%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 strong, highly specific description that clearly articulates concrete capabilities and includes excellent natural trigger terms covering AWS S3 security auditing. Its main weakness is the absence of an explicit 'Use when...' clause, which would help Claude know precisely when to select this skill over others. The specificity of tools and security concerns makes it very distinctive.
Suggestions
Add an explicit 'Use when...' clause, e.g., 'Use when the user asks about S3 security, bucket access audits, public bucket exposure, or AWS storage compliance checks.'
| Dimension | Reasoning | Score |
|---|---|---|
Specificity | Lists multiple specific concrete actions: audit S3 bucket permissions, identify publicly accessible buckets, overly permissive ACLs, misconfigured bucket policies, missing encryption settings. Also names specific tools: AWS CLI, S3audit, and Prowler. | 3 / 3 |
Completeness | Clearly answers 'what does this do' with detailed capabilities, but lacks an explicit 'Use when...' clause or equivalent trigger guidance. The 'when' is only implied by the nature of the actions described. | 2 / 3 |
Trigger Term Quality | Includes strong natural keywords users would say: 'S3 bucket permissions', 'publicly accessible buckets', 'ACLs', 'bucket policies', 'encryption settings', 'AWS CLI', 'S3audit', 'Prowler', 'least-privilege'. These cover a wide range of terms a user concerned about S3 security would naturally use. | 3 / 3 |
Distinctiveness Conflict Risk | Highly specific niche: AWS S3 bucket security auditing with named tools (S3audit, Prowler). Very unlikely to conflict with other skills given the narrow focus on S3 permissions, ACLs, and bucket policies. | 3 / 3 |
Total | 11 / 12 Passed |
Implementation
77%Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
This is a strong, highly actionable skill with executable commands throughout and a well-sequenced multi-step audit workflow. Its main weaknesses are moderate verbosity from sections that explain concepts Claude already knows (Key Concepts table, Tools & Systems descriptions) and a monolithic structure that could benefit from splitting reference material into separate files. The common scenario with pitfall warnings adds practical value.
Suggestions
Remove or significantly trim the 'Key Concepts' table—Claude already knows what bucket policies, ACLs, and server-side encryption are. Keep only project-specific or non-obvious definitions.
Move the 'Tools & Systems' and 'Common Scenarios' sections to separate referenced files (e.g., TOOLS.md, SCENARIOS.md) to reduce the main skill's token footprint and improve progressive disclosure.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The skill is generally well-structured but includes some unnecessary sections like the 'Key Concepts' table defining terms Claude already knows (e.g., what a bucket policy is, what SSE is, what ACLs are). The 'Tools & Systems' section also restates obvious information. The 'When to Use' and 'Do not use' sections are somewhat verbose. However, the core workflow steps are reasonably efficient. | 2 / 3 |
Actionability | Every workflow step includes fully executable bash commands with proper AWS CLI syntax, JMESPath queries, and inline Python for policy analysis. The remediation commands in Step 7 are copy-paste ready with clear parameter structures. The Prowler commands include specific check names rather than vague references. | 3 / 3 |
Workflow Clarity | The 7-step workflow follows a logical progression from enumeration → per-bucket analysis → policy review → encryption/versioning checks → automated scanning → Access Analyzer → remediation. Each step has a clear purpose and builds on previous steps. The common scenario includes a pitfall warning about breaking public-facing applications before applying Block Public Access, serving as a validation checkpoint. The workflow is well-sequenced for a security audit. | 3 / 3 |
Progressive Disclosure | The content is entirely self-contained in a single file with no references to external files for advanced topics. The Key Concepts table, Tools & Systems section, and Common Scenarios section add significant length that could be split into separate reference files. For a skill of this length (~180 lines of substantive content), better progressive disclosure with linked references would improve navigability. | 2 / 3 |
Total | 10 / 12 Passed |
Validation
90%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 / 11 Passed
Validation for skill structure
| Criteria | Description | Result |
|---|---|---|
frontmatter_unknown_keys | Unknown frontmatter key(s) found; consider removing or moving to metadata | Warning |
Total | 10 / 11 Passed | |
- Repository
- mukul975/Anthropic-Cybersecurity-Skills
- Commit
888bbe4
- Reviewed
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