search prompt example for sources field causes HTTP 422

when using a chatbot to call the search function via this MCP the request it sent was
```
{
"query": "Tesla stock price current TSLA",
"limit": 5,
"sources": [
"web"
]
}
```

and the response was
```
{
"error": "HTTP error 422: {\"detail\":[{\"type\":\"model_attributes_type\",\"loc\":[\"body\",\"sources\",0],\"msg\":\"Input should be a valid dictionary or object to extract fields from\",\"input\":\"web\"}]}"
}
```

when the model corrected to
```
{
"query": "Tesla stock price current TSLA",
"limit": 5,
"sources": [
{
"type": "web"
}
]
}
```

the response returned was correct

Inspect the search tool's source schema and the prompt or example that documents the sources field. Reproduce the HTTP 422 with the array of strings, then verify that the documented example uses source objects and the corrected request succeeds.

Written by the indexing model from the issue text.