# MCP Tool Contract: compare-iterations
## Overview
Compares duas iterações side-by-side (comparação A/B) para analisar evoluções de prompts, dimensões e parâmetros.
## Tool Name
`compare-iterations`
## Description
Compare two iterations side-by-side (A/B comparison)
## Input Parameters
| Parameter | Type | Required | Description |
|-----------|------|----------|-------------|
| `sessionId` | string | Yes | Session identifier |
| `iterationIndex1` | number | Yes | 0-based index of first iteration |
| `iterationIndex2` | number | Yes | 0-based index of second iteration |
## Output Schema
```typescript
{
status: 'success' | 'error',
data?: {
iteration1: {
index: number,
prompt: string,
dimensions: {
width: number,
height: number
},
parameters: Record<string, any>,
timestamp: string,
image: string // base64 encoded
},
iteration2: {
index: number,
prompt: string,
dimensions: {
width: number,
height: number
},
parameters: Record<string, any>,
timestamp: string,
image: string // base64 encoded
},
differences: {
promptChanged: boolean,
promptDiff: {
added: string[],
removed: string[],
modified: string[]
},
dimensionsChanged: boolean,
dimensionsDetail: {
width: { from: number, to: number },
height: { from: number, to: number }
},
parametersChanged: boolean,
parametersDetail: Record<string, { from: any, to: any }>
}
},
error?: string
}
```
## Use Cases
- **Analyze prompt evolution**: Compare iteration 2 vs iteration 5 to see which prompts changes improved output
- **Review parameter adjustments**: Identify which settings modifications affected results
- **Visual comparison**: Side-by-side images to evaluate quality differences
- **Decision making**: Determine which iteration was more successful before rollback
## Notes
- Returns detailed diff of all changes between iterations
- Both images included as base64 for immediate visualization
- Useful for understanding which adjustments improved output
- Non-destructive operation, does not modify session state
## Error Handling
- Invalid sessionId → error status with message
- iterationIndex1 or iterationIndex2 out of bounds → error status with message
- iterationIndex1 equals iterationIndex2 → error status with message
