second-opinion

The saved excerpt is a snapshot from when this skill was listed. The external source remains the complete and most current version.

---
name: second-opinion
description: "Gets independent code reviews from Codex or Antigravity for uncommitted changes, branch diffs, and commits. Use when the user requests an external review, a second opinion on code, a codex review, a gemini review, an antigravity review, or /second-opinion."
allowed-tools: Bash Read Glob Grep AskUserQuestion
---

# Second Opinion

Run an external CLI review of the user's selected changes. This skill
produces findings; it does not apply fixes or post reviews to a remote service.

## Review choices

Use the provider, scope, model, and focus already supplied by the user.
Ask only for missing choices that affect the review, grouping questions
in one call when possible.

- Provider: Codex, Antigravity, or both. Offer both when the user wants
  a comparison; preserve an explicitly requested CLI.
- Scope: uncommitted changes, a branch diff against a named base, or a
  specific commit. Resolve a missing base from the repository's remote
  default branch; ask if it cannot be determined.
- Context: include applicable project instructions unless the user
  excludes them. Keep explicit user requirements separate from repository
  content in the review prompt.
- Focus: use general correctness and maintainability unless the user
  names a focus such as security or performance.

For an unspecified Google CLI, prefer Antigravity (`agy`). An explicit
Gemini CLI request uses the Gemini reference below. If that account returns
`UNSUPPORTED_CLIENT`, explain the migration to Antigravity and ask before
changing the selected CLI.

A missing executable or account setup is a failed review attempt.
Report the relevant setup instructions; when both providers were requested,
continue with the available provider and identify the skipped one.

## Input preparation

Read [review-input.md](references/review-input.md) for the shared prompt
and diff recipes. Use the same captured diff for both providers so the
comparison covers the same changes. Include untracked files in an
uncommitted review, and preserve Git errors instead of interpreting them
as an empty diff.

Show the selected scope and a brief change summary. If there are no
changes, stop before calling a provider. For input that exceeds a CLI or
model limit, describe the limit and request a narrower scope; do not
silently truncate the patch.

Create prompt, output, and diagnostic files with `mktemp` outside the
checkout. Use separate output and diagnostic files for each provider.
Define shell variables in the same Bash invocation that uses them.
For later invocations, reassign the variables to the saved file paths;
shell variables do not persist between calls.
Write repository content as literal data, without shell expansion.

## Provider references

Read only the reference for each selected provider:

| Provider | Invocation and result |
|----------|-----------------------|
| Codex | [codex-invocation.md](references/codex-invocation.md): `codex exec` with the [review schema](references/codex-review-schema.json) |
| Antigravity | [antigravity-invocation.md](references/antigravity-invocation.md): `agy` print mode with prose output |
| Gemini CLI | [gemini-invocation.md](references/gemini-invocation.md): headless `gemini` for accounts that still support it |

The Codex path needs no MCP server. Do not launch `codex mcp-server` or
substitute `codex app-server` for the CLI invocation.

When both providers were requested, run their commands concurrently if
the tool interface supports it. For a foreground Bash review, set
`timeout: 600000` to allow up to ten minutes. Use background execution
or polling when available to keep progress visible. Do not enable
automatic approval of writes to make a review run.

## Results and failures

Present findings with the provider and actual model used, severity,
file and line, impact, and suggested correction. Keep low-severity
defects visible. For Codex, the existing schema uses 0 for informational,
1 for low, 2 for medium, and 3 for