エージェントが使用できるツール（機能）の実装方法です。
# tools/base.py
from abc import ABC, abstractmethod
class Tool(ABC):
"""ツールの抽象基底クラス"""
# ツールのメタ情報（サブクラスで定義）
name: str = ""
description: str = ""
input_schema: dict = {}
@abstractmethod
def execute(self, **kwargs) -> str:
"""ツールを実行し、結果を文字列で返す"""
pass
def to_dict(self) -> dict:
"""LLM に送信するためのツール定義を返す"""
return {
"name": self.name,
"description": self.description,
"input_schema": self.input_schema,
}# tools/read_file.py
from .base import Tool
class ReadFileTool(Tool):
"""ファイル読み込みツール"""
name = "read_file"
description = "Read the contents of a file at the specified path."
input_schema = {
"type": "object",
"properties": {
"path": {
"type": "string",
"description": "The path to the file to read",
},
},
"required": ["path"],
}
def execute(self, path: str) -> str:
"""ファイルを読み込んで内容を返す"""
try:
with open(path, "r", encoding="utf-8") as f:
content = f.read()
return content
except FileNotFoundError:
return f"Error: File not found: {path}"
except PermissionError:
return f"Error: Permission denied: {path}"
except Exception as e:
return f"Error: {type(e).__name__}: {e}"# tools/write_file.py
from pathlib import Path
from .base import Tool
class WriteFileTool(Tool):
"""ファイル書き込みツール"""
name = "write_file"
description = "Write content to a file at the specified path."
input_schema = {
"type": "object",
"properties": {
"path": {
"type": "string",
"description": "The path to the file to write",
},
"content": {
"type": "string",
"description": "The content to write to the file",
},
},
"required": ["path", "content"],
}
def execute(self, path: str, content: str) -> str:
"""ファイルに内容を書き込む"""
try:
# 親ディレクトリを作成
Path(path).parent.mkdir(parents=True, exist_ok=True)
with open(path, "w", encoding="utf-8") as f:
f.write(content)
return f"Successfully wrote to {path}"
except Exception as e:
return f"Error: {type(e).__name__}: {e}"# tools/execute_command.py
import subprocess
from .base import Tool
class ExecuteCommandTool(Tool):
"""シェルコマンド実行ツール"""
name = "execute_command"
description = "Execute a shell command and return the output."
input_schema = {
"type": "object",
"properties": {
"command": {
"type": "string",
"description": "The shell command to execute",
},
},
"required": ["command"],
}
# セキュリティのためブロックするパターン
BLOCKED_PATTERNS = [
"rm -rf /",
"rm -rf ~",
"sudo rm",
"> /dev/sda",
]
def execute(self, command: str) -> str:
"""コマンドを実行して出力を返す"""
# ブロックパターンのチェック
for pattern in self.BLOCKED_PATTERNS:
if pattern in command:
return f"Error: Blocked command pattern: {pattern}"
try:
result = subprocess.run(
command,
shell=True,
capture_output=True,
text=True,
timeout=30, # 30秒でタイムアウト
)
output = result.stdout
if result.stderr:
output += f"\n[stderr]\n{result.stderr}"
if result.returncode != 0:
output += f"\n[exit code: {result.returncode}]"
return output or "(no output)"
except subprocess.TimeoutExpired:
return "Error: Command timed out after 30 seconds"
except Exception as e:
return f"Error: {type(e).__name__}: {e}"# tool_registry.py
class ToolRegistry:
"""ツールを登録・管理するクラス"""
def __init__(self):
self.tools: dict[str, Tool] = {}
def register(self, tool: Tool) -> None:
"""ツールを登録"""
self.tools[tool.name] = tool
def register_all(self, tools: list[Tool]) -> None:
"""複数のツールを一括登録"""
for tool in tools:
self.register(tool)
def get_tool_definitions(self) -> list[dict]:
"""LLM に送信するためのツール定義リストを返す"""
return [tool.to_dict() for tool in self.tools.values()]
def execute(self, tool_name: str, tool_input: dict) -> str:
"""ツールを実行"""
if tool_name not in self.tools:
return f"Error: Unknown tool '{tool_name}'"
tool = self.tools[tool_name]
return tool.execute(**tool_input)
def list_tools(self) -> list[str]:
"""登録されているツール名のリストを返す"""
return list(self.tools.keys())# main.py
tool_registry = ToolRegistry()
tools = [
ReadFileTool(),
WriteFileTool(),
ListFilesTool(),
ExecuteCommandTool(),
]
tool_registry.register_all(tools)JSON Schema 形式でパラメータを定義します。
input_schema = {
"type": "object",
"properties": {
# 必須パラメータ
"path": {
"type": "string",
"description": "The path to the file",
},
# オプションパラメータ（デフォルト値付き）
"encoding": {
"type": "string",
"description": "File encoding (default: utf-8)",
"default": "utf-8",
},
# 列挙型
"mode": {
"type": "string",
"enum": ["read", "write", "append"],
"description": "File open mode",
},
# 配列
"paths": {
"type": "array",
"items": {"type": "string"},
"description": "List of file paths",
},
},
"required": ["path"], # 必須パラメータのリスト
}tools/に新しいファイルを作成Toolクラスを継承name,description,input_schemaを定義execute()メソッドを実装tools/__init__.pyでエクスポートmain.pyで登録
# tools/my_tool.py
from .base import Tool
class MyTool(Tool):
name = "my_tool"
description = "Does something useful."
input_schema = {
"type": "object",
"properties": {
"param1": {"type": "string", "description": "..."},
},
"required": ["param1"],
}
def execute(self, param1: str) -> str:
# 実装
return f"Result: {param1}"# tools/__init__.py
from .my_tool import MyTool
__all__ = [..., "MyTool"]# main.py
from .tools import MyTool
tools = [..., MyTool()]def execute(self, **kwargs) -> str:
try:
# メイン処理
result = do_something(**kwargs)
return result
except SpecificError as e:
# 特定のエラー
return f"Error: {e}"
except Exception as e:
# 予期しないエラー
return f"Error: {type(e).__name__}: {e}"常に文字列を返すことで、エージェントループが壊れないようにします。
- 02-tool-use.md - ツールが呼び出される仕組み