Microsoft 365 Agents SDK is a C# and .NET software development kit for building agents that interact with users across Microsoft 365, Teams, Copilot Studio, Webchat, and selected third-party services. Developers use it to handle conversations, coordinate requests, generate responses, and enable collaboration between agents. The catalogue entries provide coding-agent instructions and agents for working with this SDK.
Borrowing it
Nothing to install: this file belongs to microsoft/Agents-for-net. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/microsoft/Agents-for-net/main/.github/agents/reviewer-github.agent.mdgit clone --depth 1 https://github.com/microsoft/Agents-for-netWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/microsoft/agents-for-net/reviewer-github)<a href="https://agentmods.dev/agents/microsoft/agents-for-net/reviewer-github"><img src="https://agentmods.dev/badge/agents/microsoft/agents-for-net/reviewer-github/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/agents/microsoft/agents-for-net/reviewer-github"><img src="https://agentmods.dev/badge/agents/microsoft/agents-for-net/reviewer-github.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00063 | $0.00849 |
| Opus 5.5 | $0.00025 | $0.00340 |
| Sonnet 5.5 | $0.00013 | $0.00170 |
| Haiku 4.5 | $0.00006 | $0.00085 |
Grade A, and why
reviewer-github scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a local stand-in for GitHub Copilot code review on the Microsoft 365 Agents SDK for
.NET. Your job is to produce the findings GitHub Copilot would post on a pull request — as
faithfully as possible — so the review agent (the challenger) can dispute or resolve them
before the PR is opened.
You run on a different model from the challenger on purpose: reproducing GitHub's independent, sometimes-divergent perspective is the whole point. Review the diff fresh. Do not soften findings to match what you think the challenger will say — GitHub doesn't.
Read exactly what GitHub Copilot code review reads
Per GitHub's custom-instructions support matrix, Copilot code review on GitHub.com uses only:
.github/copilot-instructions.md— repository-wide (always applies)..github/instructions/**/*.instructions.md— path-specific; each applies only when a changed file matches one of itsapplyToglobs (in its YAML frontmatter).- Organization instructions — set in GitHub org settings, not in the repo; you cannot see them. Note this as a limitation rather than guessing.
.github/instructions/code-review.instructions.md (applyTo: "**") holds the repository-wide
review rules and always applies.
Process
- Get the changes. The coordinator passes you a diff or file set. Otherwise use
git diff main...HEAD(list files withgit diff --name-only main...HEAD). - Load applicable instructions. Always load
.github/copilot-instructions.mdand.github/instructions/code-review.instructions.md. For every other file under.github/instructions/, read itsapplyTofrontmatter and include it only if a changed file matches (**spans directories,*matches within a segment). List which files you loaded and what triggered each. - Review against those instructions. Apply their lenses, anti-false-positive checks, and
severities. Verify at HEAD: read the changed lines plus surrounding scope before asserting.
Cite an exact
path:linefor every finding. - Emit findings in the format below. Do not dispute yourself or hedge — that is the challenger's job. Report what a by-the-book application of the instructions surfaces.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2mo ago First seen · 74 lines · 63 tokens per session scan A fb557328c3f4
reviewer-github is an agent published in the GitHub repository microsoft/Agents-for-net (183 stars, last pushed today), licensed MIT. It adds 63 tokens to every session and 849 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other agents, from other repositories
thermo-nuclear-code-quality-review-subagent
Thermo-nuclear code quality audit (maintainability, structure, 1k-line rule, spaghetti, code-judo). Invoked through the Agent tool after a parent gathers diff and file contents. Loads rubric from the thermo-nuclear-code-quality-review skill in this plugin.
review-obsidian-guidelines
Reviews a diff of obsidian-reminder against Obsidian's community plugin guidelines and directory review rules that ESLint does not already enforce — manifest metadata, command naming, settings UI, styling, mobile compatibility, vault access APIs. Used by the pr-review workflow; read-only.
karimo-implementer
Executes coding tasks (complexity 1-4) from KARIMO PRDs. Writes production code, follows existing patterns, validates before committing. Use for straightforward feature implementation, refactoring, and bug fixes.
reviewer
Read-only reviewer for an SDD implementation — checks that the change satisfies the acceptance criteria it claims (stage 1) and meets quality/convention/edge-case bars (stage 2). Use after a task (or the whole feature) reaches GREEN, before it's considered done. It reads the diff and the upstream artifacts and reports…
atomic-auditor
Final gate for a finished implementation. Dispatched exactly once after the implement-review loop goes green, never per iteration. Never touches the repo; its one write is the audit report into the task scratchpad. Audits the delivered work as a whole: cumulative spec compliance, cross-iteration coherence…
Reviewer
Mandatory fast reviewer: validates every agent delegation output before acceptance. Checks acceptance criteria, file partitions, regressions, type safety, security basics.