Triage a build / compile / restore / WarnAsError failure from its MSBuild binary log. Fetches the binlog (a local build's, or a failed dotnet/fsharp Azure DevOps PR build's published artifact) and analyzes it live via the `binlog-mcp` MCP server — structured errors, root-cause diagnosis, and an MSBuild perf X-ray. NOT for test failures or CheckCodeFormatting: a build binlog has no errors there.

Implementation details for EF Core SaveChanges and the update pipeline. Use when changing CommandBatchPreparer, UpdateSqlGenerator, ModificationCommand, or related classes.

Use this skill to triage an incoming issue on the EF Core repo (bug report or feature request). Sets the issue type (bug/feature), assigns EF area labels, attempts to arrive at a minimal repro reproducing the bug, checks whether it represents a regression, finds possible duplicates, etc.

Implementation details for the EF Core dotnet-ef CLI and tooling. Use when changing dotnet-ef commands, the ef wrapper, EFCore.Tools (PMC), or EFCore.Tasks MSBuild integration.

Implementation details for EF Core test infrastructure. Use when changing test fixtures, SQL baseline assertions, test helpers, the test class hierarchy, or when adding new tests.

Implementation details for the Microsoft.Data.Sqlite ADO.NET provider. Use when changing files under `src/Microsoft.Data.Sqlite.Core/`.

Create EF Core PRs targeting servicing release branches (release/*). Use when working on a PR that targets a release branch, backporting a fix from main, or when the user mentions servicing, patch, or release branch.

Implementation details for EF Core scaffolding (reverse engineering). Use when changing ef dbcontext scaffold pipeline implementation, database schema reading, CSharpModelGenerator, or related classes.

Run ApiChief in the EF Core repo to emit baselines, summaries, deltas, review files, or breaking-change checks. Use when refreshing `*.baseline.json`, preparing API review artifacts, or validating API changes.

Implementation details for EF Core LINQ query translation, SQL generation, and bulk operations (ExecuteUpdate/ExecuteDelete). Use when changing expression visitors, SqlExpressions, QuerySqlGenerator, ShaperProcessingExpressionVisitor, UpdateExpression, DeleteExpression, or related classes.

Implementation details for EF Core model building. Use when changing ConventionSet, ModelBuilder, IConvention implementations, ModelRuntimeInitializer, RuntimeModel, or related classes.

Implementation details for EF Core migrations. Use when changing MigrationsSqlGenerator, model diffing, migration operations, HistoryRepository, the Migrator or related classes.

Create new Agent Skills for GitHub Copilot. Use when asked to create, scaffold, or add a skill. Generates SKILL.md with frontmatter, directory structure, and optional resources.

Create VS Code file-based instructions (.instructions.md files). Use when asked to create, scaffold, or add file-based instructions for Copilot. Generates .instructions.md with YAML frontmatter and background knowledge content.

Create GitHub Actions workflows for CI, automation, or PR management. Use when asked to create, scaffold, or add a GitHub Actions workflow (.yml file under .github/workflows/).

Create custom GitHub Copilot agents. Use when asked to create, scaffold, or configure a custom agent, declarative agent, or @-invokable chat participant for GitHub Copilot.

Implementation details for the EF Core Azure Cosmos DB provider. Use when changing Cosmos-specific code.

Implementation details for EF Core change tracking. Use when changing InternalEntityEntry, ChangeDetector, SnapshotFactoryFactory, or related entity state, snapshot, or property accessor code.

Generate release notes for the dotnet/diagnostics repository. Use when asked to generate release notes, a release summary, or a changelog.

Investigate source-build failures in dotnet/dotnet VMR CI builds. USE FOR any mention of "prebuilt", "source-build/source-only failure", "source-build-assets (SBRP)", "poison", source-build repo build ordering problems, binary detection/removal, or any build leg failures that only occur in `SB_*` job names. DO NOT USE FOR regular CI test failures, codeflow staleness, dependency flow tracing, crash dumps, or general NuGet package management unrelated to source-build.