feat: Add x-ms-agentid header for MCP platform calls

[pontemonti]

Overview

Port of Node.js SDK PR #183 - adds x-ms-agentid header to all outbound HTTP requests to the MCP platform for agent identification.

Related PR: microsoft/Agent365-nodejs#183

Problem Statement

The MCP platform needs to identify which agent is making tooling requests for:

• Logging and diagnostics
• Usage analytics

Solution

Add the x-ms-agentid header to outbound requests with the following priority:

1. Agent Blueprint ID from TurnContext (agenticAppBlueprintId)
2. Agent Blueprint ID from token (xms_par_app_azp claim)
3. Entra Application ID from token (appid or azp claim)
4. Application name from entry assembly

Changes

Runtime Package

• Add GetAgentIdFromToken() - extracts agent ID from JWT with priority fallback
• Add GetApplicationName() - returns entry assembly name

Tooling Package

• Add AgentIdHeader constant (x-ms-agentid)
• Update HttpContextHeadersHandler to add the header when authToken is available
• Pass authToken to HttpContextHeadersHandler constructor
• Add InternalsVisibleTo for test access

Tests

• Add 11 unit tests for GetAgentIdFromToken() covering all priority paths
• Add test for GetApplicationName()

Documentation

• Add PRD document adapted for .NET

Testing

• All 548 existing tests pass
• Build succeeds with no errors or warnings
• 3 code review iterations completed

Breaking Changes

None - this is a backward-compatible addition.

[Copilot]

Pull request overview

This PR adds the x-ms-agentid header to all outbound HTTP requests to the MCP platform for agent identification, porting functionality from the Node.js SDK (PR #183). The header enables the MCP platform to identify calling agents for logging, diagnostics, and usage analytics.

Changes:

• Added utility methods in Runtime package to extract agent identifiers from JWT tokens and application assembly
• Updated HttpContextHeadersHandler to inject the x-ms-agentid header with priority-based fallback logic
• Added comprehensive unit tests for token parsing with 11 test cases covering all priority paths
• Created PRD documentation describing the technical design and implementation strategy

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/Tooling/Core/docs/prd-x-ms-agentid-header.md	PRD documentation detailing the technical design, priority logic, and implementation approach for the x-ms-agentid header feature
src/Tooling/Core/Utils/Constants.cs	Added AgentIdHeader constant for the x-ms-agentid header name
src/Tooling/Core/Services/McpToolServerConfigurationService.cs	Updated to pass authToken to HttpContextHeadersHandler constructor
src/Tooling/Core/Microsoft.Agents.A365.Tooling.csproj	Added InternalsVisibleTo attribute for test project access
src/Tooling/Core/Handlers/HttpContextHeadersHandler.cs	Implemented header injection logic with priority fallback: TurnContext blueprint ID > token claims > application name
src/Tests/Runtime.Tests/UtilityTests.cs	Added 11 unit tests for GetAgentIdFromToken() covering all claim priority paths and edge cases, plus test for GetApplicationName()
src/Runtime/Core/Utility.cs	Added GetAgentIdFromToken() method to extract agent ID from JWT with claim priority, and GetApplicationName() to get entry assembly name