Add .NET low-level tool-definition E2E test [6/6]

[edburns]

Summary

Adds .NET low-level tool-definition E2E coverage and includes the session-lifecycle replay prompt alignment fix.

This PR is related to issue #1682 but does not fix #1682.

What changed

• Adds Low_Level_Tool_Definition coverage in:
  • dotnet/test/E2E/ToolsE2ETests.cs
• Includes session-lifecycle prompt alignment fix:
  • dotnet/test/E2E/SessionLifecycleE2ETests.cs
• Reuses the shared low-level snapshot introduced by PR Add Java low-level tool definition E2E test and skill [1/6] #1721:
  • test/snapshots/tools/low_level_tool_definition.yaml
• Aligns low-level tool definitions with snapshot-exercised paths only and validates keyword argument handling in the search tool.

Dependency / sequencing

• Depends on PR Add Java low-level tool definition E2E test and skill [1/6] #1721 being merged first (already merged).
• Part of the Start iterating on #1682 On branch edburns/1682-java-tool-ergonomics #1692 breakout plan (PR 6 of 6).

Related

• Issue: Java: Ergonomics: Defining tools #1682 (not fixed by this PR)
• PR Add Java low-level tool definition E2E test and skill [1/6] #1721
• Original combined PR: Start iterating on #1682 On branch edburns/1682-java-tool-ergonomics #1692

[Copilot]

⚠️ Not ready to approve

The updated session-lifecycle prompt no longer matches the existing replay snapshot, which will cause the E2E test to fail unless the snapshot is updated in the same PR.

Pull request overview

Adds .NET E2E coverage for low-level tool definition APIs using the shared replay snapshot, and tweaks a session-lifecycle E2E prompt string.

Changes:

• Add a new .NET E2E test Low_Level_Tool_Definition that defines custom tools via AIFunctionFactory and asserts tool argument handling + resulting assistant content.
• Change the second session’s persistence “activity” prompt in the session-lifecycle E2E test (but this currently risks desync with the existing replay snapshot).

File summaries

File	Description
dotnet/test/E2E/ToolsE2ETests.cs	Adds a new low-level tool-definition E2E test that exercises multiple custom tools and validates keyword argument plumbing.
dotnet/test/E2E/SessionLifecycleE2ETests.cs	Updates the second session prompt used to generate persistence activity for the replay-based lifecycle test.

Copilot's findings

• Files reviewed: 2/2 changed files
• Comments generated: 1

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[github-actions]

Cross-SDK Consistency Review ✅

Overview

This PR is the last ([6/6]) in a coordinated series that adds low_level_tool_definition E2E coverage to all six SDK implementations. With the sibling PRs #1724 (Go), #1725 (Node.js), #1726 (Python), and #1727 (Rust) also open, the full SDK matrix will have equivalent coverage — good planning.

The .NET implementation is consistent with the reference Java test (LowLevelToolDefinitionIT.java) in the key respects:

• Reuses the shared test/snapshots/tools/low_level_tool_definition.yaml snapshot
• Exercises the same two tools (set_current_phase / search_items) that the snapshot covers
• Uses the idiomatic .NET raw-arg access pattern (AIFunctionArguments) analogous to Java's invocation.getArguments()
• Asserts currentPhase, content keywords, and AIFunctionArguments keyword value — matching Java's assertions

Minor Observations

1. Scope difference vs Java (intentional, per PR description)

Java's LowLevelToolDefinitionIT registers a third tool — ToolDefinition.createOverride("grep", ...) — to test the built-in tool override path via the low-level API. The .NET test intentionally omits this ("aligned with snapshot-exercised paths only"), which is reasonable since grep is never invoked in the snapshot and the override scenario is already covered by ToolsE2ETests.Overrides_Built_In_Tool_With_Custom_Tool. No action needed, but worth noting for future alignment.

2. PR description mentions SessionLifecycleE2ETests.cs — not present in the diff

The PR body says:

Includes session-lifecycle prompt alignment fix:
dotnet/test/E2E/SessionLifecycleE2ETests.cs

However, only dotnet/test/E2E/ToolsE2ETests.cs appears in the file-changed list. If the session-lifecycle fix was intentionally dropped or moved to a separate PR, it may be worth updating the description to avoid confusion for reviewers and future readers.

Summary

The change is well-scoped, follows established patterns, and the broader series ensures all SDKs will have equivalent low-level tool definition coverage. No cross-SDK API consistency issues found.

Generated by SDK Consistency Review Agent for issue #1728 · sonnet46 2.3M · ◷