| name | second-opinions |
| description | Get validation from a different AI model before committing major changes — detects available LLM CLIs and routes to the best one. |
| display_name | Second Opinions |
| brand_color | #4F46E5 |
| local_only | false |
| group | For Anyone |
| usage | /second-opinions:run |
| summary | About to make a big call? Get a gut-check from a second AI with a different perspective before you commit. |
| favorite | true |
| default_prompt | Get a second opinion on this implementation or design decision and summarize the strongest agreement, disagreement, and actionable feedback. |
Second Opinions
Get validation from a different AI before committing. Any single model — regardless of which one is running — has blind spots shaped by its training, context, and the conversation so far. A different architecture, temperature, or framing catches different things.
When to Use
Mandatory:
- Complex multi-file changes before merge
- Design decisions with multiple valid approaches
- After 2+ hours on a single approach (tunnel vision risk)
- Security-sensitive or performance-critical code
Skip for: trivial fixes, style questions, crystal-clear requirements
Agent Detection
Use the bundled detection script, with an inline fallback if SKILL_DIR isn't set:
bash "${SKILL_DIR}/scripts/detect-llms.sh" --quiet 2>/dev/null || \
for t in agent claude codex llm; do command -v "$t" >/dev/null 2>&1 && echo "$t"; done
Use the first one found. If none are available, tell the user and skip this step. Treat agent as a router, not a requirement: direct claude -p, codex exec, or any subscribed local-agent CLI is valid. Do not call Anthropic/Claude models through OpenRouter; use local claude -p directly or via agent <opus|sonnet|haiku> --no-fallback, or skip Claude.
Codex caveat: codex loads ~/.codex/config.toml → your CLAUDE.md, so by default it delegates the review back to the cheap-model toolchain (quick-check) — silently defeating the point of a different model's opinion. The detect script already adds --ignore-user-config; also end the prompt with: "Do this review YOURSELF — do not delegate to any other tool or model." Heavy reviews can exceed 10 min (use -c model_reasoning_effort="xhigh", run in background).
Model Selection
Second opinions are about deep analysis, not speed. Use the smartest model available:
| Tool | For deep analysis | For quick checks |
|---|
agent | agent --frontier (codex subscription / GPT-5.5; no Anthropic OpenRouter) | agent --fast (deepseek-v4-flash) |
agent when Claude is wanted | agent opus --no-fallback (local claude -p; fails closed) | agent sonnet --no-fallback |
codex | GPT-5.5 — see Codex caveat above | — |
When this skill is invoked for pre-merge review, design validation, or architecture decisions, prefer agent --frontier, or codex for a genuinely different architecture. If the desired second opinion is specifically Claude, use agent opus --no-fallback; the agent command must route Claude through local claude -p, never OpenRouter. For quick sanity checks, agent --fast is fine.
How to Ask
The prompt is the same regardless of agent — adapt the invocation to whatever's available. The detect-llms.sh script outputs NAME|INVOKE_PATTERN|MODEL_FAMILY|NOTES — use the INVOKE_PATTERN field, substituting {prompt} with your actual prompt.
Pre-Merge Review (Most Common)
Show the diff and ask for a production-readiness check:
Review my git changes for production readiness.
Show the diff from main and check for:
- Correctness and edge cases
- Architecture and design
- Performance implications
- Security concerns
Design Decision Validation
Describe the options and constraints, then ask: What trade-offs am I not seeing?
Targeted Question
Ask one specific question about the implementation — don't fish for general feedback.
Interpreting Results
The other agent is a collaborator, not an authority. Classify each piece of feedback:
| Category | Action |
|---|
| Must-fix | Bug, security issue, correctness problem → implement immediately |
| Should-fix | Genuine simplification, better error handling → implement if clean |
| Nice-to-have | Alternative approach, style preference → mention to user |
| Reject | Over-engineering, conflicts with project conventions → skip with reason |
If the other agent and your analysis disagree, explain the disagreement to the user and let them decide.
The Red Flags
These thoughts mean STOP and get a second opinion:
- "It works in my tests" — tests only prove known scenarios
- "I've spent 3 hours on this" — sunk cost isn't validation
- "I'm confident this is right" — confidence correlates with blind spots
- "It's obviously the best approach" — obvious to you ≠ optimal
5 minutes of external validation prevents hours of debugging.
