# Echo Tool
Echo a message back with optional transformations, repetition, and structured output support. This is a utility tool useful for testing MCP connectivity and demonstrating tool patterns.
## Process Flow
```mermaid
flowchart TD
A[Start] --> B[Validate Input]
B --> C{Input Valid?}
C -->|No| D[Return Error]
C -->|Yes| E[Send Progress: 0%]
E --> F{Uppercase?}
F -->|Yes| G[Convert to Uppercase]
F -->|No| H[Keep Original]
G --> I[Repeat Message N Times]
H --> I
I --> J[Create Structured Output]
J --> K[Create Resource Links]
K --> L[Send Progress: 100%]
L --> M[Return Success with Data]
```
## Input Schema
| Parameter | Type | Required | Default | Description |
| ----------- | ------- | -------- | ------- | -------------------------------------------- |
| `message` | string | Yes | - | The message to echo back (1-1000 characters) |
| `repeat` | integer | No | `1` | Number of times to repeat the message (1-10) |
| `uppercase` | boolean | No | `false` | Whether to convert the message to uppercase |
## Output Schema
| Field | Type | Description |
| ------------------ | ------- | -------------------------------------------- |
| `originalMessage` | string | The original input message |
| `processedMessage` | string | The processed output message |
| `repeat` | number | Number of repetitions applied |
| `uppercase` | boolean | Whether uppercase transformation was applied |
| `length` | number | Length of the final processed message |
## Examples
**Example 1: Simple echo**
```json
{
"input": {
"message": "Hello, World!"
},
"output": {
"originalMessage": "Hello, World!",
"processedMessage": "Hello, World!",
"repeat": 1,
"uppercase": false,
"length": 13
}
}
```
**Example 2: Echo with repetition and uppercase**
```json
{
"input": {
"message": "Hello",
"repeat": 3,
"uppercase": true
},
"output": {
"originalMessage": "Hello",
"processedMessage": "HELLO HELLO HELLO",
"repeat": 3,
"uppercase": true,
"length": 17
}
}
```
## Error Handling
| Error | Cause | Resolution |
| ---------------------- | ---------------------------------- | ----------------------------------------- |
| `Message is required` | Empty or missing message parameter | Provide a non-empty message string |
| `Message too long` | Message exceeds 1000 characters | Reduce message length to under 1000 chars |
| `Invalid repeat value` | Repeat value outside 1-10 range | Use a repeat value between 1 and 10 |
## Tags
`utility`, `example`, `text`
