---
title: "Advanced Tool Configuration"
description: "Advanced features and patterns for Agency Swarm tools."
icon: "wand-magic-sparkles"
---

Besides standard Pydantic features, you can also use a special `ToolConfig` class to customize tool behavior within the framework:

## Available `ToolConfig` Parameters

The following parameters are supported, with version compatibility noted:

| Name               | Type    | Description | When to Use | Default Value |
|--------------------|---------|-------------|-------------|---------------|
| `one_call_at_a_time` | `bool` | Prevents concurrent execution for a specific tool. If you want to adjust parallel tool calling for all tools, prefer configuring `model_settings=ModelSettings(parallel_tool_calls=...)`. Use this per-tool setting when you need strict sequencing. | Use for database operations, API calls with rate limits, or actions that depend on previous results. | `False`         |
| `strict`             | `bool` | Enables strict mode, which ensures the agent will always provide **perfect** tool inputs that 100% match your schema. Has limitations. See [OpenAI Docs](https://platform.openai.com/docs/guides/structured-outputs#supported-schemas). | Use for mission-critical tools or tools that have nested Pydantic model schemas.                     | `False`         |

## Usage

To use one of the available parameters, simply add a `class ToolConfig` block to your tool class:

```python
class MyCustomTool(BaseTool):
    # ...

    class ToolConfig:
        one_call_at_a_time = True
        strict = False

    async def run(self):
        # ...
```