What problem does it solve? Building an MCP server in C# is only half the job — without automated tests, you cannot verify that tools behave correctly, that the server lists and invokes tools properly over the MCP protocol, or that changes don't break existing behavior. This Skill provides a complete testing workflow for .NET MCP servers, from isolated unit tests to full protocol-level integration tests. ## Core Features & Use Cases - Unit Testing of Tool Methods: Test individual MCP tool methods directly with xUnit, Moq, and FluentAssertions, including mocking HttpClient dependencies via HttpMessageHandler. - Integration Testing via MCP Protocol: Validate tool listing with ListToolsAsync and invocation with CallToolAsync using the MCP client SDK, in-memory ClientServerTestBase, or WebApplicationFactory for HTTP servers. - Evaluations for LLM Tool Use: Design read-only, deterministic evaluation questions in XML format to measure how well an LLM uses your server's tools. - Use Case: You built a product catalog MCP server and want CI coverage. Use this Skill to scaffold a test project, write unit tests for each tool, add in-memory integration tests verifying the protocol, and author evaluation questions for quality measurement. ## Quick Start Ask the AI to write unit and integration tests for your C# MCP server project using xUnit and the MCP client SDK.
