Update file-based app skill to mention features from 10.0.300

[jjonescz]

Resolves #150.
Resolves #531.
Resolves #255.

[github-actions]

Note

This PR is from a fork and modifies infrastructure files (eng/ or .github/).

Changes to infrastructure typically need to be submitted from a branch in dotnet/skills (not a fork) so that CI workflows run with the correct permissions and secrets.

Please consider recreating this PR from an upstream branch. If you don't have push access to dotnet/skills, ask a maintainer to push your branch for you.

[Copilot]

Pull request overview

Updates the csharp-scripts skill documentation and evaluation scenarios to use “file-based app” terminology and document new multi-file composition capabilities introduced in .NET SDK 10.0.300.

Changes:

• Renames user-facing wording from “C# scripts” to “file-based C# apps” and clarifies when to use vs. avoid this workflow.
• Documents new directives/features (#:include, #:exclude, and #:ref, including transitive directives guidance).
• Adds a new eval scenario intended to exercise multi-file composition using include/exclude directives.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
tests/dotnet/csharp-scripts/eval.yaml	Renames an existing scenario and adds a new scenario for multi-file file-based apps.
plugins/dotnet/skills/csharp-scripts/SKILL.md	Updates terminology and expands guidance to cover .NET 10.0.300 multi-file composition and #:ref.
.github/CODEOWNERS	Changes ownership for the skill/tests from @dotnet/roslyn to @dotnet/run-file.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[jjonescz]

/evaluate

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[jjonescz]

/evaluate

[github-actions]

Skill Validation Results

Skill	Scenario	Quality	Skills Loaded	Overfit	Verdict
csharp-scripts	Avoid activating for language-agnostic calendar script	5.0/5 → 4.3/5 🔴	✅ csharp-scripts; tools: skill, create	🟡 0.29	❌
csharp-scripts	Test a C# language feature with a file-based app	2.7/5 ⏰ → 3.7/5 🟢	✅ csharp-scripts; tools: skill, create, edit	🟡 0.29	✅
csharp-scripts	Compose a file-based app from helper files	1.7/5 ⏰ → 2.3/5 ⏰ 🟢	✅ csharp-scripts; tools: skill, edit / ✅ csharp-scripts; tools: stop_bash, skill, edit	🟡 0.29	✅ [1]

[1] ⚠️ High run-to-run variance (CV=1.30) — consider re-running with --runs 5

⏰ timeout — run(s) hit the (120s) scenario timeout limit; scoring may be impacted by aborting model execution before it could produce its full output (increase via timeout in eval.yaml)

Model: claude-opus-4.6 | Judge: claude-opus-4.6

🔍 Full Results - additional metrics and failure investigation steps

▶ Sessions Visualisation -- interactive replay of all evaluation sessions

[jjonescz]

@dotnet/run-file @dotnet/skills-csharp-language-reviewers for review, thanks

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

[jjonescz]

/evaluate

[github-actions]

Skill Validation Results

Skill	Scenario	Quality	Skills Loaded	Overfit	Verdict
csharp-scripts	Avoid activating for language-agnostic calendar script	5.0/5 → 5.0/5	ℹ️ not activated (expected) / ✅ csharp-scripts; tools: skill, create, edit	🟡 0.36	❌
csharp-scripts	Test a C# language feature with a file-based app	3.0/5 → 4.0/5 🟢	✅ csharp-scripts; tools: skill, create, edit / ✅ csharp-scripts; tools: skill, create, edit, view	🟡 0.36	✅
csharp-scripts	Compose a file-based app from helper files	1.7/5 ⏰ → 5.0/5 🟢	✅ csharp-scripts; tools: skill / ✅ csharp-scripts; tools: skill, edit	🟡 0.36	✅

⏰ timeout — run(s) hit the (120s) scenario timeout limit; scoring may be impacted by aborting model execution before it could produce its full output (increase via timeout in eval.yaml)

Model: claude-opus-4.6 | Judge: claude-opus-4.6

🔍 Full Results - additional metrics and failure investigation steps

▶ Sessions Visualisation -- interactive replay of all evaluation sessions