> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/MicrosoftDocs/azure-ai-docs/llms.txt
> Use this file to discover all available pages before exploring further.

# File Search Tool

> Retrieve knowledge from uploaded documents using hybrid vector and keyword search in Microsoft Foundry agents.

# File Search Tool

File Search augments agents with knowledge from documents like product information, internal documentation, or user-provided files.

## How It Works

The file search tool implements retrieval best practices:

1. **Rewrites queries** for optimal search
2. **Breaks down complex queries** into multiple parallel searches
3. **Runs hybrid search** (vector + keyword) across vector stores
4. **Reranks results** to select most relevant content
5. **Injects into context** for agent to use

**Default settings**:

* Chunk size: 800 tokens
* Chunk overlap: 400 tokens
* Embedding model: text-embedding-3-large (256 dimensions)
* Max chunks in context: 20

## Quick Start

<CodeGroup>
  ```python Python theme={null}
  from azure.ai.projects.models import FileSearchTool, FilePurpose

  # Upload file
  file = project.agents.files.upload_and_poll(
      file_path="product_catalog.pdf",
      purpose=FilePurpose.AGENTS
  )

  # Create file search tool
  file_search = FileSearchTool(file_ids=[file.id])

  agent = project.agents.create_agent(
      model="gpt-4o",
      name="product-expert",
      instructions="Answer questions using uploaded product files",
      tools=file_search.definitions,
      tool_resources=file_search.resources,
  )
  ```
</CodeGroup>

## Vector Stores

Vector stores enable file search capabilities:

* Store up to 10,000 files per vector store
* Attach one vector store to agent
* Attach one vector store to thread
* Automatic parsing, chunking, and embedding

<Warning>
  Maximum file size: 512 MB
  Maximum tokens per file: 5,000,000
</Warning>

## Setup Dependencies

### Basic Setup

* Microsoft-managed storage and search

### Standard Setup

* Uses your Azure Blob Storage
* Uses your Azure AI Search resource
* Full data control

See [Standard Setup](/foundry/agents/standard-setup) for details.