AI Agent 的手脚、接口和操作手册：一篇讲透 Tools、MCP 与 Skills

{

"name": "query_sales",

"arguments": {

"month": "2026-09"

}

}

import json

import os

from openai import OpenAI

client = OpenAI()

MODEL = os.environ["OPENAI_MODEL"]

# 模拟数据

SALES_DATA = {

"2026-09": {"sales": 820000, "orders": 1260, "customers": 486},

"2026-10": {"sales": 690000, "orders": 1080, "customers": 421},

}

def query_sales(month: str) -> dict:

if month not in SALES_DATA:

raise ValueError(f"无 {month} 数据")

return {"month": month, **SALES_DATA[month]}

TOOL_DEFINITIONS = [{

"type": "function",

"function": {

"name": "query_sales",

"description": "查询指定月份销售数据",

"parameters": {

"type": "object",

"properties": {"month": {"type": "string"}},

"required": ["month"],

},

},

}]

TOOL_FUNCTIONS = {"query_sales": query_sales}

def run_agent(user_input: str) -> str:

messages = [{"role": "user", "content": user_input}]

for _ in range(8):

response = client.chat.completions.create(

model=MODEL, messages=messages, tools=TOOL_DEFINITIONS, tool_choice="auto"

)

message = response.choices[0].message

messages.append(message)

if not message.tool_calls:

return message.content or ""

for tool_call in message.tool_calls:

name = tool_call.function.name

try:

arguments = json.loads(tool_call.function.arguments)

result = TOOL_FUNCTIONS[name](**arguments)

tool_output = {"ok": True, "data": result}

except Exception as exc:

tool_output = {"ok": False, "error": str(exc)}

messages.append({

"role": "tool",

"tool_call_id": tool_call.id,

"content": json.dumps(tool_output, ensure_ascii=False),

})

raise RuntimeError("调用次数超限")

from mcp.server.fastmcp import FastMCP

mcp = FastMCP("Sales Data Server")

@mcp.tool()

def query_sales(month: str) -> dict:

"""查询指定月份销售统计数据"""

# 逻辑实现...

return {"month": month, "sales": 820000}

@mcp.tool()

def calculate_change(previous: float, current: float) -> dict:

"""计算变化额与变化率"""

# 逻辑实现...

return {"change": current - previous}

if __name__ == "__main__":

mcp.run(transport="stdio")

import asyncio

from mcp import ClientSession, StdioServerParameters

from mcp.client.stdio import stdio_client

async def main():

server_params = StdioServerParameters(command="python", args=["server.py"])

async with stdio_client(server_params) as (read_stream, write_stream):

async with ClientSession(read_stream, write_stream) as session:

await session.initialize()

tools = await session.list_tools()

print([t.name for t in tools.tools])

result = await session.call_tool("query_sales", {"month": "2026-10"})

print(result.content)

asyncio.run(main())

---

name: sales-analysis

description: 分析月度销售表现并生成报告

---

## 执行步骤

1. 确认分析月份与统计口径

2. 查询本期与上期数据

3. 计算关键指标变化

4. 定位异常区域或产品

5. 生成标准化报告

## 约束

- 禁止编造数据

- 区分相关性与因果关系

明确单一真实业务任务的输入输出标准。

实现少量高可靠性的 Python Tools。

在多应用共享需求下，封装 MCP Server。

针对高频复杂任务，沉淀 Skills。

最后完善工作流、治理与测试体系。