Fix Metadata delegation in DelegatingMcpServerTool/Prompt/Resource

[Copilot]

• Add Metadata override to DelegatingMcpServerTool, DelegatingMcpServerPrompt, DelegatingMcpServerResource
• Add thorough tests in DelegatingMcpServerToolTests.cs, DelegatingMcpServerPromptTests.cs, DelegatingMcpServerResourceTests.cs
• Use BindingFlags.DeclaredOnly instead of DeclaringType check in reflection-based override validation
• Fixed net472 build failure
• All tests pass

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[stephentoub]

@copilot please improve the tests around these delegating types in a way that validates all members are appropriately overridden

[Copilot]

@copilot please improve the tests around these delegating types in a way that validates all members are appropriately overridden

Added DelegatingMcpServerPrimitiveTests with a reflection-based test that validates all virtual/abstract members declared on the base types (McpServerTool, McpServerPrompt, McpServerResource) are overridden in the corresponding delegating types. This will catch future regressions if new members are added to base classes but not delegated. See 610c3b8.

[stephentoub]

@copilot please split the tests into files based on each type. If there's already a test file for the type, add the relevant test(s) there instead

[Copilot]

@copilot please split the tests into files based on each type. If there's already a test file for the type, add the relevant test(s) there instead

Split the tests into the existing per-type files: McpServerToolTests, McpServerPromptTests, and McpServerResourceTests. Removed DelegatingMcpServerPrimitiveTests.cs. See 42d685f.

[stephentoub]

@copilot tests for Delegating McpServerTool should really be in a DelegatingMcpServerToolTests.cs file; similarly for prompt and resource. Please move all such tests into the right test file/class.

[jeffhandley]

@copilot See #1338 (comment). There was a typo when you were mentioned, but that's fixed now. Address that feedback please.

[Copilot]

@copilot tests for Delegating McpServerTool should really be in a DelegatingMcpServerToolTests.cs file; similarly for prompt and resource. Please move all such tests into the right test file/class.

Moved the tests into dedicated files: DelegatingMcpServerToolTests.cs, DelegatingMcpServerPromptTests.cs, and DelegatingMcpServerResourceTests.cs. Reverted McpServerToolTests.cs, McpServerPromptTests.cs, and McpServerResourceTests.cs to their original state. See d6d7123.

[jeffhandley]

API changes look good to me assuming the expanded test coverage doesn't uncover anything that needs to be changed further.