Patch the code so `scripts/local-checks.sh` passes, after /implement-mainspec — a narrow post-implement polish specialist. Reads the (remediation-rich) check failures, fixes the underlying cause, never silences a check, re-verifies, and commits. Invoked headless by the dispatcher's two-strike local-checks gate; the dispatcher owns the retry counter. Triggers - fix-local-checks, fix lint, fix local checks, fix typecheck, make checks pass, post-implement polish (project)

Patch the code so `scripts/local-checks.sh` passes, after /implement-mainspec — a narrow post-implement polish specialist. Reads the (remediation-rich) check failures, fixes the underlying cause, never silences a check, re-verifies, and commits. Invoked headless by the dispatcher's two-strike local-checks gate; the dispatcher owns the retry counter. Triggers - fix-local-checks, fix lint, fix local checks, fix typecheck, make checks pass, post-implement polish (project)

Respond to an automated reviewer's findings on the current feature PR — a narrow, headless responder. Triages each reviewer finding into Clear / Ambiguous / Complex / Out-of-PRD-Scope, then acts — fixes the cause and pushes (diff-only) for Clear, posts one in-thread reply for the rest. Skips findings it already handled. Invoked headless by the dispatcher's feedback gate; the dispatcher owns the round counter and the STUCK escalation. Triggers - address-feedback, address review comments, respond to PR review, handle reviewer findings, PR feedback loop (project)

Respond to an automated reviewer's findings on the current feature PR — a narrow, headless responder. Triages each reviewer finding into Clear / Ambiguous / Complex / Out-of-PRD-Scope, then acts — fixes the cause and pushes (diff-only) for Clear, posts one in-thread reply for the rest. Skips findings it already handled. Invoked headless by the dispatcher's feedback gate; the dispatcher owns the round counter and the STUCK escalation. Triggers - address-feedback, address review comments, respond to PR review, handle reviewer findings, PR feedback loop (project)

Reviews a NuGet/NuGet.Client pull request like a senior maintainer — reviews in an isolated workspace by default, or against the reviewer's existing clone (self-review / local changes), builds and tests the affected projects, traces changes across files, and returns high-signal, severity-tagged findings with a merge verdict. Invoke explicitly with a PR number or branch.

Enable C# nullable reference types on files that still have `#nullable disable` in the NuGet.Client codebase. Use this skill whenever the user asks to enable nullable, migrate nullable, remove `#nullable disable`, annotate nullability, or fix nullable warnings for any NuGet project or file. Also trigger when the user mentions a GitHub issue about nullable enablement, references PublicAPI.Shipped.txt annotation updates, or says things like "let's do nullable on X" or "enable nullable for these files."

Assists with reproducing and triaging NuGet restore issues. Given a GitHub issue from NuGet/Home, analyzes the issue, extracts repro-relevant data, and writes C# tests in the NuGet.Client repo that reproduce the described scenario. Use for NuGet restore bugs, error code investigations, and test authoring tasks.

Create or update a pull request using the NuGet.Client PR template. Use when asked to: create PR, open PR, push and create PR, submit PR, open pull request, send changes for review, update PR description, fix PR body, edit PR description, update the PR.

Cherry-pick (backport/forward-port) one or more commits from one branch onto another, creating a fresh branch and opening a pull request that follows the repository's conventions. Use this whenever the user wants to move, port, backport, or cherry-pick a commit or a merged PR to a release/servicing branch (e.g. "cherry-pick the latest dev commit to 7.9.x", "backport #7576 to release/8.0.x", "port that fix to the release branch"), even if they don't say the exact word "cherry-pick". If the cherry-pick hits conflicts, STOP and report back instead of trying to resolve them, unless the user explicitly asked you to resolve conflicts.

Drive the .NET SDK breaking-change documentation-and-notification process for a NuGet change that has already been implemented. Invoke this once a NuGet/Home issue (or its implementing NuGet.Client PR) is labeled `Breaking-Change`. It makes sure the correct documentation issues are filed/completed (the NuGet NUxxxx reference-docs issue and the official dotnet/docs breaking-change issue) and helps author the draft notification email to the .NET Breaking Change Notifications alias. Trigger on phrases like "breaking change process", "file the breaking change doc issue", "the issue got the Breaking-Change label", "draft the breaking change email", or "notify dotnetbcn".

Fix F# debugging issues (breakpoints, .pdb, sequence points). Build, run VS integration tests, inspect IL/PDB.

Performs multi-agent, multi-model code review of F# compiler PRs across 19 dimensions including type checking, IL emission, binary compatibility, and IDE performance. Dispatches parallel assessment agents per dimension, consolidates with cross-model agreement scoring, and filters false positives. Invoke when reviewing compiler changes, requesting expert feedback, or performing pre-merge quality checks.

Write release notes for completed changes. Use when PR modifies tracked paths and needs release notes entry.

Debug and fix --realsig+ (RealInternalSignature) codegen bugs in IlxGen — MethodAccessException / FieldAccessException / TypeAccessException at runtime, IL `private` vs `assembly` visibility, closure and TLR-lift placement (cloc / NestedTypeRefForCompLoc / effectiveCloc / moduleCloc). Use when a program compiles cleanly but crashes only under --realsig+, when IL accessibility differs between realsig modes, or when reasoning about where compiler-synthesized closures/state-machines/quotation helpers are nested.

Use when drafting, proposing, creating, or editing prose for a dotnet/fsharp GitHub PR or issue — body, title, comment, review summary, edits — including bare asks like "open a PR", "ship this", "write up what I did", "summarise the change", "reply on the PR", "edit the issue body", "gh pr create", "gh pr comment", "gh pr edit --body", "gh issue comment", "gh pr review --body". Primary use case is PR descriptions; same rules apply to PR/issue comments and review summaries. Not for labels, reviewers, merging, or code-review findings (just the prose write-up of them).

Retrieve and analyze Azure DevOps build failures for GitHub PRs. Use when CI fails. CRITICAL: Collect ALL errors from ALL platforms FIRST, write hypotheses to file, then fix systematically.

Write a postmortem for a regression that escaped to production, broke real users, and traces back to a design flaw worth documenting for future implementors. Only invoke after confirming no existing postmortem or doc covers the same root cause.

Fix ILVerify baseline failures when IL shape changes (codegen, new types, method signatures). Use when CI fails on ILVerify job.

Investigate compiler failures, test errors, or unexpected behavior through systematic minimal reproduction, 3-hypothesis testing, and verification. Always re-run builds and tests after changes.

Always invoke after editing `.fs` files under `src/Compiler/`. Fast parse/typecheck without `dotnet build`, plus symbol references and inferred type hints. Use whenever the user asks about F# errors, compile errors, type inference, finding usages, or renaming a symbol in the compiler tree.