SKILL.md
ABOUTME: Measures cognitive load of codebases using 8 dimensions, producing a 0-1000 score
ABOUTME: Sigmoid-normalized metrics with P90 weighting, Python calculator for deterministic results
Cognitive Load Analyzer
Produce a deterministic Cognitive Load Index (0-1000) with per-dimension breakdown and actionable recommendations.
When to run: before major refactors, when onboarding to unfamiliar codebases, during architecture reviews, or to track complexity trends over time.
Scoring Scale
| CLI Score | Rating |
|---|---|
| 0-100 | Excellent |
| 101-250 | Good |
| 251-400 | Moderate |
| 401-600 | Concerning |
| 601-800 | Poor |
| 801-999 | Severe |
Score is asymptotic: 0 and 1000 are unreachable by design. Cap at 999.
The 8 Dimensions
| # | Dimension | Weight | Sigmoid(mid, steep) | Raw Input |
|---|---|---|---|---|
| D1 | Structural Complexity | 0.20 | (15, 0.15) | 0.4mean + 0.6P90 of CogC per function |
| D2 | Nesting Depth | 0.15 | (4, 0.5) | 0.3mean + 0.7P90 of max nest per function |
| D3 | Volume/Size | 0.12 | composite | 4 sub-sigmoids (func LOC, file LOC, params, methods) |
| D4 | Naming Quality | 0.15 | (2, 0.5) for single-char | Static heuristics + optional LLM assessment (60/40) |
| D5 | Coupling | 0.12 | (8, 0.2) efferent | Efferent coupling, imports, instability risk |
| D6 | Cohesion | 0.10 | (0.5, 4) class | LCOM per class or module cohesion ratio |
| D7 | Duplication | 0.08 | (5, 0.3) | Duplication % * 100 |
| D8 | Navigability | 0.08 | composite | Dir depth, files/dir P90, file size CV |
Weights sum to 1.00.
Formula derivations
Per-dimension sub-weights, the sigmoid definition, P90 weighting, and the aggregation/interaction-penalty math live in references/formulas.md. The lib/cli_calculator.py script is the deterministic source of truth; read the reference only to audit or explain a score.
Workflow
Phase 1: Discovery (2-3 turns)
- Detect language(s) from file extensions
- Count files, directories, LOC
- Probe tools:
command -v lizard radon jscpd gocyclo - If >100K LOC, activate deterministic sampling (SHA-256 hash mod 100 < 30, plus all files >200 LOC)
Phase 2: Dimension Collection (8-12 turns)
For each D1-D8:
- Run tool or fallback command to collect raw metrics
- Invoke calculator:
uv run --no-project python3 <skilldir>/lib/clicalculator.py normalize-d<N> '<json>' - Record: raw metrics, normalized score, tool used, warnings
Tool priority: lizard (30+ languages) > language-specific (radon, gocyclo, eslint) > grep/awk/find heuristics.
Phase 3: Aggregation (2-3 turns)
- Pass all scores:
uv run --no-project python3 <skilldir>/lib/clicalculator.py aggregate '{"D1": ..., "D8": ...}' - Identify top 3 dimensions and top 5 worst offenders
- Produce report
Calculator Commands
Script path: skills/cognitive-load-analyzer/lib/cli_calculator.py
| Command | Input JSON | Output |
|---|---|---|
normalize-d1 |
{"complexity_scores": [...]} |
d1, raw, mean, p90 |
normalize-d2 |
{"nesting_depths": [...]} |
d2, raw, mean, p90 |
normalize-d3 |
{"funclocs": [...], "filelocs": [...], "paramcounts": [...], "methodsper_class": [...]} |
d3 + sub-scores |
normalize-d4-static |
{"shortnameproportion": f, "abbreviationdensity": f, "singlecharper100loc": f, "consistency_ratio": f} |
d4_static + components |
normalize-d4-llm |
{"d4static": f, "llmscore": f} |
d4 combined |
normalize-d5 |
{"efferentcouplings": [...], "importsperfile": [...], "afferentcouplings": [...]} |
d5 + components |
normalize-d6-class |
{"lcom_values": [...]} |
d6, mean_lcom |
normalize-d6-module |
{"avgexportsusedtogether": f, "totalexports": f} |
d6, module_cohesion |
normalize-d7 |
{"duplication_pct": f} |
d7 (input as fraction, e.g. 0.05) |
normalize-d8 |
{"maxdirectorydepth": f, "filesperdirectory": [...], "file_sizes": [...]} |
d8 + components |
aggregate |
{"D1": f, ..., "D8": f} |
cli_score, rating, penalty |
sample-files |
{"filepaths": [...], "filelocs": {...}} |
selected files |
All output is {"ok": true, "result": {...}} or {"ok": false, "error": "..."}.
Report Format
# Cognitive Load Index Report
## Summary
- CLI Score: {score} / 1000 ({rating})
- Language: {lang} | Files: {count} | LOC: {loc}
- D4 Mode: {llm_model | static_heuristic}
## Dimension Breakdown
| Dimension | Raw | Normalized | Weighted | Rating |
|-----------|-----|------------|----------|--------|
| D1-D8 rows... |
| Interaction Penalty | {pairs} | | +{pts} | |
| **TOTAL** | | | **{cli}** | **{rating}** |
## Top 5 Worst Offenders
1. {file:function} - {metrics}
## Recommendations
1. {action targeting highest-contributing dimension}
## Methodology
- Tools: {list} | Fallbacks: {list or "none"}
- Sampling: {full | SHA256 deterministic N%}
Recommended Actions by Dimension
| Dimension | High Score Indicates | Fix |
|---|---|---|
| D1 | Complex control flow | Extract methods, replace conditionals with polymorphism |
| D2 | Deep nesting | Guard clauses (early returns), extract nested blocks |
| D3 | Oversized units | Split functions (<30 LOC), files (<300 LOC), parameter objects |
| D4 | Poor identifiers | Rename for intent, eliminate abbreviations |
| D5 | Tight dependencies | Dependency inversion, interfaces, reduce imports |
| D6 | Mixed responsibilities | SRP, split classes by responsibility |
| D7 | Duplicated code | Extract shared logic, parameterize |
| D8 | Poor organization | Flatten dirs, group related files |
Prioritize higher-weighted dimensions (D1, D4) over lower ones (D7, D8).
Polyglot Codebases
Analyze each language subset independently, aggregate weighted by LOC: CLIpolyglot = sum(LOClang / LOCtotal * CLIlang)
Large Codebase Sampling (>100K LOC)
selected = [f for f in sorted(files)
if int(hashlib.sha256(f.encode()).hexdigest()[:8], 16) % 100 < 30]
# Plus all files > 200 LOC
Deterministic: identical results across runs for same codebase.