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Surface server-level instructions in MCP tool discovery #263

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110 changes: 110 additions & 0 deletions ...ts/Microsoft.Agents.A365.Tooling.Tests/Services/McpToolServerConfigurationServiceTests.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -833,6 +833,116 @@ public async Task SendChatHistoryAsync_HttpRequestExceptionWithStatusCode_Return
httpEx.Should().NotBeNull();
httpEx!.StatusCode.Should().Be(HttpStatusCode.ServiceUnavailable);
}

[Fact]
public async Task ListToolServersAsync_GatewayResponseWithInstructions_PopulatesInstructions()
{
// Arrange
var configMock = new Mock<IConfiguration>();
configMock.Setup(c => c["MCP_PLATFORM_ENDPOINT"]).Returns("https://test.example.com");

const string expectedInstructions = "Use these tools to interact with Salesforce data. Always call GetTables first.";
var responseJson = JsonSerializer.Serialize(new
{
mcpServers = new[]
{
new
{
mcpServerName = "mcp_SalesforceServer",
url = "https://test.example.com/agents/servers/mcp_SalesforceServer",
id = "sf-1",
scope = "api://audience/Tools.ListInvoke.All",
audience = "api://audience",
publisher = "Microsoft",
instructions = expectedInstructions
}
}
});

var mockHttpMessageHandler = new Mock<HttpMessageHandler>();
mockHttpMessageHandler
.Protected()
.Setup<Task<HttpResponseMessage>>(
"SendAsync",
ItExpr.IsAny<HttpRequestMessage>(),
ItExpr.IsAny<CancellationToken>())
.ReturnsAsync(() => new HttpResponseMessage
{
StatusCode = HttpStatusCode.OK,
Content = new StringContent(responseJson, Encoding.UTF8, "application/json")
});

using var httpClient = new HttpClient(mockHttpMessageHandler.Object);
var httpClientFactoryMock = new Mock<IHttpClientFactory>();
httpClientFactoryMock.Setup(f => f.CreateClient(It.IsAny<string>()))
.Returns(httpClient);

var service = new McpToolServerConfigurationService(
_loggerMock.Object,
configMock.Object,
_serviceProviderMock.Object,
httpClientFactoryMock.Object);

// Act
var servers = await service.ListToolServersAsync("agent-123", "token-456");

// Assert
servers.Should().ContainSingle();
servers[0].mcpServerName.Should().Be("mcp_SalesforceServer");
servers[0].instructions.Should().Be(expectedInstructions);
}

[Fact]
public async Task ListToolServersAsync_GatewayResponseWithoutInstructions_LeavesInstructionsNull()
{
// Arrange
var configMock = new Mock<IConfiguration>();
configMock.Setup(c => c["MCP_PLATFORM_ENDPOINT"]).Returns("https://test.example.com");

var responseJson = JsonSerializer.Serialize(new
{
mcpServers = new[]
{
new
{
mcpServerName = "mcp_MailServer",
url = "https://test.example.com/agents/servers/mcp_MailServer",
id = "mail-1"
}
}
});

var mockHttpMessageHandler = new Mock<HttpMessageHandler>();
mockHttpMessageHandler
.Protected()
.Setup<Task<HttpResponseMessage>>(
"SendAsync",
ItExpr.IsAny<HttpRequestMessage>(),
ItExpr.IsAny<CancellationToken>())
.ReturnsAsync(() => new HttpResponseMessage
{
StatusCode = HttpStatusCode.OK,
Content = new StringContent(responseJson, Encoding.UTF8, "application/json")
});

using var httpClient = new HttpClient(mockHttpMessageHandler.Object);
var httpClientFactoryMock = new Mock<IHttpClientFactory>();
httpClientFactoryMock.Setup(f => f.CreateClient(It.IsAny<string>()))
.Returns(httpClient);

var service = new McpToolServerConfigurationService(
_loggerMock.Object,
configMock.Object,
_serviceProviderMock.Object,
httpClientFactoryMock.Object);

// Act
var servers = await service.ListToolServersAsync("agent-123", "token-456");

// Assert
servers.Should().ContainSingle();
servers[0].instructions.Should().BeNull();
}
}
}

7 changes: 7 additions & 0 deletions src/Tooling/Core/Models/MCPServerConfig.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -42,6 +42,13 @@ public class MCPServerConfig
/// </summary>
public string? publisher { get; set; }

/// <summary>
/// Gets or sets optional natural-language instructions describing how an agent should use
/// this server's tools. Surfaced by the discovery response when the server declares them;
/// null when the server provides no instructions.
/// </summary>
public string? instructions { get; set; }

/// <summary>
/// Gets or sets per-server HTTP headers, including the Authorization header populated
/// by <c>AttachPerAudienceTokensAsync</c> before tool connections are established.
Expand Down
18 changes: 16 additions & 2 deletions src/Tooling/Core/Services/McpToolServerConfigurationService.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -246,6 +246,7 @@ JsonValueKind.Object when jsonDoc.TryGetProperty("mcpServers", out var servers)
string? scope = null;
string? audience = null;
string? publisher = null;
string? instructions = null;

if (serverElement.TryGetProperty("mcpServerName", out var nameElement) &&
nameElement.ValueKind == JsonValueKind.String)
Expand Down Expand Up @@ -284,6 +285,11 @@ JsonValueKind.Object when jsonDoc.TryGetProperty("mcpServers", out var servers)
{
publisher = publisherElement.GetString();
}
if (serverElement.TryGetProperty("instructions", out var instructionsElement) &&
instructionsElement.ValueKind == JsonValueKind.String)
{
instructions = instructionsElement.GetString();
}

// Both Name and Endpoint are required
if (string.IsNullOrWhiteSpace(name) || string.IsNullOrWhiteSpace(endpoint))
Expand All @@ -298,7 +304,8 @@ JsonValueKind.Object when jsonDoc.TryGetProperty("mcpServers", out var servers)
id = id ?? string.Empty,
scope = scope,
audience = audience,
publisher = publisher
publisher = publisher,
instructions = instructions
};
}
catch (Exception)
Expand All @@ -323,6 +330,7 @@ JsonValueKind.Object when jsonDoc.TryGetProperty("mcpServers", out var servers)
string? scope = null;
string? audience = null;
string? publisher = null;
string? instructions = null;

if (serverElement.TryGetProperty("mcpServerName", out var nameElement) &&
nameElement.ValueKind == JsonValueKind.String)
Expand Down Expand Up @@ -361,6 +369,11 @@ JsonValueKind.Object when jsonDoc.TryGetProperty("mcpServers", out var servers)
{
publisher = publisherElement.GetString();
}
if (serverElement.TryGetProperty("instructions", out var instructionsElement) &&
instructionsElement.ValueKind == JsonValueKind.String)
{
instructions = instructionsElement.GetString();
}
Comment on lines +372 to +376

// Both Name and ServerName are required
if (string.IsNullOrWhiteSpace(name))
Expand All @@ -378,7 +391,8 @@ JsonValueKind.Object when jsonDoc.TryGetProperty("mcpServers", out var servers)
id = id ?? string.Empty,
scope = scope,
audience = audience,
publisher = publisher
publisher = publisher,
instructions = instructions
};
}
catch (Exception)
Expand Down