Harness Simplify

---
name: harness-simplify
description: This skill should be used when the user asks to "/harness-simplify", "simplify the harness", "remove harness component", "stress test the harness", "do we need the evaluator", "is the planner necessary", "optimize harness cost", or wants to test whether a harness component is still needed. Implements progressive simplification — removing one component at a time and comparing quality.
argument-hint: [component to test: planner | evaluator | rounds]
allowed-tools: [Read, Write, Edit, Bash, Glob, Grep, Agent, AskUserQuestion]
---

# Harness Simplify — Component Stress Testing

## Overview

Every harness component encodes an assumption about what the model can't do on its own. This skill tests those assumptions by removing one component, re-running a task, and comparing quality.

> "Find the simplest solution possible, and only increase complexity when needed."

## Execution

### Step 1: Identify Target Component

If the user specified a component, use it. Otherwise, ask which to test:

| Component | Assumption it encodes | Cost saved if removed |
|-----------|----------------------|----------------------|
| `evaluator` | Model can't judge its own work | ~$3-10 per eval round + time |
| `planner` | Model can't expand briefs well inline | ~$0.50 + 5 min |
| `rounds` | Model needs external feedback loops | Proportional to rounds saved |

Recommended test order: `rounds` → `evaluator` → `planner` (least to most impactful).

### Step 2: Establish Baseline

Check for existing harness results in `.harness/`:
- If a completed run exists, use its eval scores as baseline
- If not, inform the user a baseline run is needed first

Record baseline scores:
```
Baseline (all components):
  Design Quality: X/5
  Originality: X/5
  Craft: X/5
  Functionality: X/5
  Cost: $X
  Time: Xm
```

### Step 3: Run Without Component

Temporarily disable the component in `.harness/config.json` and dispatch a new harness run on the same brief.

- **Remove evaluator**: Generator builds, no QA pass. User or simplified heuristic checks quality.
- **Remove planner**: Generator works directly from user brief (no spec expansion).
- **Reduce rounds**: Set `maxRounds: 1` (single build + single eval).

### Step 4: Compare Results

If evaluator is enabled for comparison, dispatch it on both outputs. Present side-by-side:

```
                    With Component    Without Component
Design Quality:     4/5               3/5
Originality:        3/5               3/5
Craft:              4/5               4/5
Functionality:      4/5               2/5
Cost:               $125              $72
Time:               3h50m             2h07m
```

### Step 5: Decision

- **Quality drop > 1 point** on any dimension → Component is load-bearing. Keep it.
- **Quality holds** (within 1 point across all dimensions) → Component encodes a stale assumption. Recommend disabling.

### Step 6: Record and Apply

Write results to `.harness/simplification-log.md` (append, don't overwrite).

If the user agrees to disable the component, update `.harness/config.json`:
```json
{
  "evaluator": false
}
```

This persists across future harness runs in this project.

## Additional Resources

### Reference Files
- **`references/evolution-history.md`** — How the original Anthropic harness evolved from V1 to V2