vscode-copilotstudio: Agent for Claude Code

.github/agents/reviewer-gpt.agent.md

reviewer-gpt is an agent for Claude Code from microsoft/vscode-copilotstudio. It costs 51 tokens per session (1,111 once invoked), scanned A, original, MIT.

A read-only code-review guide that uses a second, independent model to inspect code changes for correctness, security, design, and project conventions. It requires checking the surrounding code before reporting a problem.

In plain words
What is it for?
Use it to review a diff, trace all callers, check limits and guards, inspect HTTP resilience settings, and identify verified concerns without modifying the code.
Why use it?
It helps catch issues that one reviewer may overlook while reducing false alarms caused by ignoring existing safeguards or how code is actually called.

Agent for Claude Code ✓ vendor

Written for Claude Code: user-invocable in frontmatter. Also seen: model in frontmatter.

This is microsoft/vscode-copilotstudio's own configuration. It tells Claude Code how to work on vscode-copilotstudio itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything vscode-copilotstudio configures →

About the project

microsoft/vscode-copilotstudio is a Visual Studio Code extension for developing Microsoft Copilot Studio agents. It lets users view agents in their environment, clone their editable components, and work on knowledge sources, actions, topics, and triggers as files. The catalogue entries provide instructions, agents, and a skill for using the extension.

microsoft/vscode-copilotstudio · 115 stars · on GitHub

Reuse

Borrowing it

Nothing to install: this file belongs to microsoft/vscode-copilotstudio. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/microsoft/vscode-copilotstudio/main/.github/agents/reviewer-gpt.agent.md
Clone the repo
git clone --depth 1 https://github.com/microsoft/vscode-copilotstudio

Made for: Claude Code.

Wrote 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.

agentmods badge for reviewer-gpt

README.md
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Your own site
<a href="https://agentmods.dev/agents/microsoft/vscode-copilotstudio/reviewer-gpt"><img src="https://agentmods.dev/badge/agents/microsoft/vscode-copilotstudio/reviewer-gpt/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.

agentmods 80×15 button for reviewer-gpt

Your own site · 80×15
<a href="https://agentmods.dev/agents/microsoft/vscode-copilotstudio/reviewer-gpt"><img src="https://agentmods.dev/badge/agents/microsoft/vscode-copilotstudio/reviewer-gpt.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 51 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,111 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00051 $0.01111
Opus 5.5 $0.00020 $0.00444
Sonnet 5.5 $0.00010 $0.00222
Haiku 4.5 $0.00005 $0.00111

Measured 1mo ago against content hash 15d3f63d9196, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

reviewer-gpt 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 1mo 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.github/agents/reviewer-gpt.agent.md · 72 lines

How it starts

The opening of the file, as written. The whole thing — 72 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an adversarial reviewer running on a different model from reviewer-opus, specifically to catch issues a single model would anchor past. Approach the diff fresh, without assuming another reviewer's findings are right or wrong.

Anti-False-Positive Rules (MANDATORY)

Historical false-positive rate without verification: 71%. You MUST perform ALL of these checks before reporting ANY finding:

  1. Check for guards before flagging complexity — Look for HashSet visited tracking, depth/level caps, size limits (.Take(n)), and early break. If guards exist, the finding is invalid.
  2. Trace the call site, not just the method — Find ALL callers. Determine frequency: per-request (hot) vs background/startup (cold). State the call frequency in the finding.
  3. Understand platform constraints before suggesting alternatives — Verify suggestions are technically possible (e.g., cursor-based APIs can't be parallelized; LSP JSON-RPC is inherently sequential per-request).
  4. Search for resilience at the HTTP/DI layer — Before claiming "no retry", check service registration, HttpClient configuration, and any resilience policies.
  5. Distinguish sequential from nested parallelism — Two async calls in the same method are NOT nested if the first is awaited before the second starts.
  6. Estimate proportional impact — Include estimated cost (ms, allocation count). Sorting 3 items or traversing 100 nodes once is not worth flagging.

Rules

  • Read-only. Never edit.
  • Verify at HEAD before flagging: read the changed code plus its enclosing scope (20-30 lines above each flagged line) and nearby comments. Confirm the problem is real before asserting it.
  • Verify import/dependency claims against the actual file before raising them — "missing import will fail the build" is a common false positive when the import is in fact present. Open the file and check.
  • No false positives: cite the exact path:line and explain the failure, or do not raise it.
  • If uncertain, do not report it. Only high-confidence findings.
  • NEVER comment on style, formatting, naming, or documentation.
  • NEVER comment on "best practices" that don't prevent actual problems.
  • Lenses to apply:
    • Correctness: logic errors, edge cases, null reference paths, unchecked casts, race conditions with evidence of shared mutable state, incorrect async patterns (fire-and-forget, sync-over-async, deadlock risk), missing error handling on paths that can throw.
    • Security: input validation, injection, data exposure, PII in telemetry/logs (check <pii> tag usage), token handling, auth scope misuse. Credential policy violations are ALWAYS Critical.
    • Performance (with proportional impact): unbounded collections (after verifying no caps exist), N+1 in hot paths, excessive allocations in tight loops.
    • Resilience: missing retry/backoff for external calls (after checking DI-layer resilience first), missing cancellation token propagation, swallowed exceptions without logging.
    • Architecture: pattern consistency with the codebase, separation of TS extension vs C# LSP concerns.
    • Convention misses lint does not catch: apply the full checklist in .github/instructions/CodeReviewPatterns.instructions.md.
  • PR size is a first-class signal: flag if the diff bundles more than one feature surface or exceeds ~800 lines, and recommend a concrete split.
  • Classify every finding: Critical / High / Medium.

Read the full file on GitHub · 72 lines

Changes

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.

  1. 1mo ago First seen · 72 lines · 51 tokens per session scan A 15d3f63d9196

Subscribe to this mod's changes

reviewer-gpt is an agent published in the GitHub repository microsoft/vscode-copilotstudio (115 stars, last pushed yesterday), licensed MIT. It adds 51 tokens to every session and 1,111 once invoked, about $0.0002 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.

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