# Phase 14: Skill Sharpener

**Purpose:** Meta-review that evaluates execution results and generates improvements.
**TS Module:** `src/tier3-compounding/skill-sharpener.ts`

## What It Does

After each skill execution, the sharpener:
1. Checks execution success — did all steps pass?
2. Evaluates quality score — is it above 0.5, 0.8?
3. Analyzes duration trends — is this run slower than average?
4. Reviews improvement suggestions — what did the execution self-report?
5. Runs full evolution analysis — what structural changes are needed?

## Review Score

```
Score = 50 (base) + qualityScore * 30 - failurePenalty + changeBonus
```

- Score < 30: no actionable improvements
- Score 30-70: minor improvements available
- Score > 70: significant improvements recommended

## Quality Gate

Improvements are only applied if:
1. Review score >= 30
2. At least one suggested change exists
3. The change is not a duplicate of an existing rule

## Usage

```bash
fable-agent skills sharpen
```

## Key Rules

- Run sharpen after every 3 skill executions
- The sharpener never modifies skills directly — it generates diffs
- Applied changes bump the skill version automatically
- Review history is persisted in `~/.fable-agent/reviews/`