Add MCP-based skills discovery (McpSkill, McpSkillsSource, McpSkillResource)

Implement Agent Skills discovery over MCP following the SEP-2640 convention:
- McpSkillsSource: reads skill://index.json to discover skills served by an MCP server
- McpSkill: lazily fetches SKILL.md content via resources/read on demand
- McpSkillResource: wraps MCP resource results (text and binary)
- Path traversal protection in get_resource for defense in depth
- Samples for Foundry Toolbox and standalone MCP skills server
- Comprehensive unit tests (514 lines)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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SergeyMenshykh
2026-05-28 19:22:01 +01:00
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| [**code_defined_skill**](code_defined_skill/) | Define skills entirely in Python code using `Skill`, `@skill.resource`, and `@skill.script` decorators. Uses a code-defined unit-converter skill. |
| [**class_based_skill**](class_based_skill/) | Define skills as Python classes using `ClassSkill` with `@ClassSkill.resource` and `@ClassSkill.script` decorators for auto-discovery. Uses a class-based unit-converter skill. |
| [**mixed_skills**](mixed_skills/) | Combine code-defined, class-based, and file-based skills in a single agent. Uses a code-defined volume-converter, a class-based temperature-converter, and a file-based unit-converter. |
| [**mcp_based_skill**](mcp_based_skill/) | Discover skills served over the [Model Context Protocol (MCP)](https://modelcontextprotocol.io) via `McpSkillsSource`. Connects to a remote MCP server that exposes skills as `skill://...` resources following the SEP-2640 convention. |
| [**script_approval**](script_approval/) | Require human-in-the-loop approval before executing skill scripts |
## Key Concepts
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# MCP-Based Agent Skills Sample
This sample demonstrates how to discover **Agent Skills served over MCP** with an `Agent`.
## What it demonstrates
- Connecting to a remote MCP server (over streamable HTTP) that exposes skill
resources following the SEP-2640 convention.
- Building a `SkillsProvider` from an `McpSkillsSource`, which reads
`skill://index.json` (SEP-2640 canonical discovery) and constructs skills from
the index entries.
- The progressive disclosure pattern across MCP: advertise → load → read
resources, exactly as for filesystem-backed skills.
## Running the Sample
### Prerequisites
- Python 3.10+
- An [Azure AI Foundry](https://ai.azure.com/) project with a deployed model
- Azure CLI authentication (`az login`)
- A running MCP server that hosts SEP-2640 skill resources (see "Providing
an MCP server" below)
### Setup
Set the following environment variables (in a `.env` file or your shell):
```powershell
$env:FOUNDRY_PROJECT_ENDPOINT="https://your-endpoint.services.ai.azure.com/api/projects/your-project"
$env:FOUNDRY_MODEL="gpt-4o-mini"
$env:MCP_SKILLS_SERVER_URL="https://your-mcp-server.example.com/mcp"
```
### Run
```powershell
python mcp_based_skill.py
```
## Providing an MCP server
This sample is a **consumer**: it does not host an MCP server itself. To try
it end-to-end you need an MCP server that exposes the SEP-2640 skill
resources (`skill://index.json` plus per-skill `SKILL.md`).
- See [`samples/02-agents/mcp/agent_as_mcp_server.py`](../../mcp/agent_as_mcp_server.py)
for an example of hosting an MCP server via the Agent Framework.
- The Model Context Protocol working group maintains reference MCP-skills
servers at
[`modelcontextprotocol/experimental-ext-skills`](https://github.com/modelcontextprotocol/experimental-ext-skills).
@@ -0,0 +1,88 @@
# Copyright (c) Microsoft. All rights reserved.
import asyncio
import os
# Uncomment this filter to suppress the experimental Skills warning before
# using the sample's Skills APIs.
# import warnings
# warnings.filterwarnings("ignore", message=r"\[SKILLS\].*", category=FutureWarning)
from agent_framework import Agent, McpSkillsSource, SkillsProvider
from agent_framework.foundry import FoundryChatClient
from azure.identity import AzureCliCredential
from dotenv import load_dotenv
from mcp.client.session import ClientSession
from mcp.client.streamable_http import streamable_http_client
"""
MCP-Based Agent Skills
This sample demonstrates how to discover Agent Skills served over the
Model Context Protocol (MCP) using :class:`McpSkillsSource`.
The sample connects to a remote MCP server that exposes skill resources
under the ``skill://`` URI scheme:
* ``skill://index.json`` — discovery document listing all skills
* ``skill://<skill-name>/SKILL.md`` — the skill instructions
To run, set ``MCP_SKILLS_SERVER_URL`` to the streamable HTTP endpoint of an
MCP server that hosts the skill resources.
"""
async def main() -> None:
"""Connect to a remote MCP skills server and run the agent."""
load_dotenv()
endpoint = os.environ["FOUNDRY_PROJECT_ENDPOINT"]
deployment = os.environ.get("FOUNDRY_MODEL", "gpt-4o-mini")
mcp_url = os.environ["MCP_SKILLS_SERVER_URL"]
print("Discovering MCP-based skills")
print("-" * 60)
# 1. Connect to the MCP server over streamable HTTP.
async with streamable_http_client(url=mcp_url) as (read, write, _), ClientSession(read, write) as session:
await session.initialize()
# 2. Build a SkillsProvider that discovers skills over MCP.
# McpSkillsSource reads skill://index.json and creates one
# McpSkill per skill-md entry; SKILL.md bodies are fetched
# on demand via resources/read.
skills_provider = SkillsProvider(McpSkillsSource(client=session))
# 3. Run the agent.
client = FoundryChatClient(
project_endpoint=endpoint,
model=deployment,
credential=AzureCliCredential(),
)
async with Agent(
client=client,
instructions="You are a helpful assistant. Use available skills to answer the user.",
context_providers=[skills_provider],
) as agent:
response = await agent.run(
"What skills do you have?"
)
print(f"Agent: {response}\n")
if __name__ == "__main__":
asyncio.run(main())
"""
Sample output:
Discovering MCP-based skills
------------------------------------------------------------
Agent: Here are your conversions:
1. **26.2 miles -> 42.16 km** (a marathon distance)
2. **75 kg -> 165.35 lbs**
Conversion factors used: miles * 1.60934 and kilograms * 2.20462.
"""