Agent skill
code-maturity-assessor
Systematic code maturity assessment using Trail of Bits' 9-category framework. Analyzes codebase for arithmetic safety, auditing practices, access controls, complexity, decentralization, documentation, MEV risks, low-level code, and testing. Produces professional scorecard with evidence-based ratings and actionable recommendations.
Install this agent skill to your Project
npx add-skill https://github.com/trailofbits/skills/tree/main/plugins/building-secure-contracts/skills/code-maturity-assessor
SKILL.md
Code Maturity Assessor
Purpose
Systematically assesses codebase maturity using Trail of Bits' 9-category framework. Provides evidence-based ratings and actionable recommendations.
Framework: Building Secure Contracts - Code Maturity Evaluation v0.1.0
How This Works
Phase 1: Discovery
Explores the codebase to understand:
- Project structure and platform
- Contract/module files
- Test coverage
- Documentation availability
Phase 2: Analysis
For each of 9 categories, I'll:
- Search the code for relevant patterns
- Read key files to assess implementation
- Present findings with file references
- Ask clarifying questions about processes I can't see in code
- Determine rating based on criteria
Phase 3: Report
Generates:
- Executive summary
- Maturity scorecard (ratings for all 9 categories)
- Detailed analysis with evidence
- Priority-ordered improvement roadmap
Rating System
- Missing (0): Not present/not implemented
- Weak (1): Several significant improvements needed
- Moderate (2): Adequate, can be improved
- Satisfactory (3): Above average, minor improvements
- Strong (4): Exceptional, only small improvements possible
Rating Logic:
- ANY "Weak" criteria → Weak
- NO "Weak" + SOME "Moderate" unmet → Moderate
- ALL "Moderate" + SOME "Satisfactory" met → Satisfactory
- ALL "Satisfactory" + exceptional practices → Strong
The 9 Categories
I assess 9 comprehensive categories covering all aspects of code maturity. For detailed criteria, analysis approaches, and rating thresholds, see ASSESSMENT_CRITERIA.md.
Quick Reference:
1. ARITHMETIC
- Overflow protection mechanisms
- Precision handling and rounding
- Formula specifications
- Edge case testing
2. AUDITING
- Event definitions and coverage
- Monitoring infrastructure
- Incident response planning
3. AUTHENTICATION / ACCESS CONTROLS
- Privilege management
- Role separation
- Access control testing
- Key compromise scenarios
4. COMPLEXITY MANAGEMENT
- Function scope and clarity
- Cyclomatic complexity
- Inheritance hierarchies
- Code duplication
5. DECENTRALIZATION
- Centralization risks
- Upgrade control mechanisms
- User opt-out paths
- Timelock/multisig patterns
6. DOCUMENTATION
- Specifications and architecture
- Inline code documentation
- User stories
- Domain glossaries
7. TRANSACTION ORDERING RISKS
- MEV vulnerabilities
- Front-running protections
- Slippage controls
- Oracle security
8. LOW-LEVEL MANIPULATION
- Assembly usage
- Unsafe code sections
- Low-level calls
- Justification and testing
9. TESTING & VERIFICATION
- Test coverage
- Fuzzing and formal verification
- CI/CD integration
- Test quality
For complete assessment criteria including what I'll analyze, what I'll ask you, and detailed rating thresholds (WEAK/MODERATE/SATISFACTORY/STRONG), see ASSESSMENT_CRITERIA.md.
Example Output
When the assessment is complete, you'll receive a comprehensive maturity report including:
- Executive Summary: Overall score, top 3 strengths, top 3 gaps, priority recommendations
- Maturity Scorecard: Table with all 9 categories rated with scores and notes
- Detailed Analysis: Category-by-category breakdown with evidence (file:line references)
- Improvement Roadmap: Priority-ordered recommendations (CRITICAL/HIGH/MEDIUM) with effort estimates
For a complete example assessment report, see EXAMPLE_REPORT.md.
Assessment Process
When invoked, I will:
-
Explore codebase
- Find contract/module files
- Identify test files
- Locate documentation
-
Analyze each category
- Search for relevant code patterns
- Read key implementations
- Assess against criteria
- Collect evidence
-
Interactive assessment
- Present my findings with file references
- Ask about processes I can't see in code
- Discuss borderline cases
- Determine ratings together
-
Generate report
- Executive summary
- Maturity scorecard table
- Detailed category analysis with evidence
- Priority-ordered improvement roadmap
Rationalizations (Do Not Skip)
| Rationalization | Why It's Wrong | Required Action |
|---|---|---|
| "Found some findings, assessment complete" | Assessment requires evaluating ALL 9 categories | Complete assessment of all 9 categories with evidence for each |
| "I see events, auditing category looks good" | Events alone don't equal auditing maturity | Check logging comprehensiveness, testing, incident response processes |
| "Code looks simple, complexity is low" | Visual simplicity masks composition complexity | Analyze cyclomatic complexity, dependency depth, state machine transitions |
| "Not a DeFi protocol, MEV category doesn't apply" | MEV extends beyond DeFi (governance, NFTs, games) | Verify with transaction ordering analysis before declaring N/A |
| "No assembly found, low-level category is N/A" | Low-level risks include external calls, delegatecall, inline assembly | Search for all low-level patterns before skipping category |
| "This is taking too long" | Thorough assessment requires time per category | Complete all 9 categories, ask clarifying questions about off-chain processes |
| "I can rate this without evidence" | Ratings without file:line references = unsubstantiated claims | Collect concrete code evidence for every category assessment |
| "User will know what to improve" | Vague guidance = no action | Provide priority-ordered roadmap with specific improvements and effort estimates |
Report Format
For detailed report structure and templates, see REPORT_FORMAT.md.
Structure:
-
Executive Summary
- Project name and platform
- Overall maturity (average rating)
- Top 3 strengths
- Top 3 critical gaps
- Priority recommendations
-
Maturity Scorecard
- Table with all 9 categories
- Ratings and scores
- Key findings notes
-
Detailed Analysis
- Per-category breakdown
- Evidence with file:line references
- Gaps and improvement actions
-
Improvement Roadmap
- CRITICAL (immediate)
- HIGH (1-2 months)
- MEDIUM (2-4 months)
- Effort estimates and impact
Ready to Begin
Estimated Time: 30-40 minutes
I'll need:
- Access to full codebase
- Your knowledge of processes (monitoring, incident response, team practices)
- Context about the project (DeFi, NFT, infrastructure, etc.)
Let's assess this codebase!
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