darkroomengineering Oracle
Three-mode expert consultation: Advice for architectural guidance, Risks for premortem analysis, Compare for weighted approach evaluation.
Product-direction asks ("what should we build", positioning, market fit) belong to /strategist — a standing persona that explores the codebase for vision framing; this skill is a single-shot engineering consult.
Mode: Advice
How to Answer
- Understand the context - What is the user trying to achieve?
- Consider trade-offs - What are the pros/cons of different approaches?
- Recommend clearly - Give a definitive recommendation
- Explain why - Justify your recommendation
- Provide examples - Show, don't just tell
Response Format
## Recommendation
[Clear recommendation]
## Why
[Reasoning and trade-offs]
## Example
[Code or implementation example]
## Alternatives
[Other valid approaches and when to use them]
Remember
- Prioritize Darkroom conventions
- Store valuable insights as learnings
Mode: Risks
Analyze potential failure modes before they happen.
Purpose
Imagine the project has failed. What went wrong?
This technique surfaces risks that optimism bias might hide.
Analysis Framework
1. Technical Risks
- What could break?
- What dependencies might fail?
- What edge cases are unhandled?
- What performance issues might emerge?
2. Integration Risks
- How might this affect other parts of the system?
- What backwards compatibility issues exist?
- What migration challenges are there?
3. Operational Risks
- What could go wrong in production?
- What monitoring is missing?
- What recovery procedures are needed?
4. User Experience Risks
- How might users misuse this?
- What accessibility issues exist?
- What confusion might arise?
Output Format
## Premortem: [Feature/Change]
### High Risk
- [Critical failure mode]
→ Mitigation: [How to prevent]
### Medium Risk
- [Significant issue]
→ Mitigation: [How to address]
### Low Risk
- [Minor concern]
→ Mitigation: [Simple fix]
### Recommendations
1. [Priority action]
2. [Secondary action]
3. [Nice to have]
When to Run
- Before large refactoring
- Before deploying new features
- Before architectural changes
- When something feels risky
Remember
- Be genuinely pessimistic
- Consider non-obvious failure modes
- Propose concrete mitigations
- Store risks as learnings for future reference
Mode: Compare
Structured approach to comparing multiple solutions using parallel evaluation, weighted scoring, and ADR output.
When to Use
- Choosing between technologies (e.g., Zustand vs Jotai vs Redux)
- Evaluating architecture patterns (e.g., monorepo vs polyrepo)
- Comparing implementation approaches for a feature
- Any decision with 2+ viable options and meaningful trade-offs
When NOT to Use
- One option is clearly superior (just recommend it)
- Trivial decisions (formatting, naming)
- Already decided by team convention
Workflow
1. Define Criteria
Establish evaluation criteria with weights (must sum to 100):
| Criterion | Weight | Description |
|------------------|--------|------------------------------------|
| Performance | 25 | Runtime speed, bundle size |
| DX | 20 | Developer experience, API quality |
| Maintainability | 20 | Long-term code health |
| Ecosystem | 15 | Community, plugins, docs |
| Migration Cost | 10 | Effort to adopt |
| Type Safety | 10 | TypeScript integration quality |
Preset Criteria Sets:
- Frontend: Performance (25), DX (20), Bundle Size (20), Accessibility (15), Ecosystem (10), Type Safety (10)
- Backend: Performance (25), Scalability (20), Maintainability (20), Security (15), Ops Complexity (10), Cost (10)
- Infrastructure: Reliability (25), Cost (20), Scalability (20), Ops Complexity (15), Vendor Lock-in (10), Migration (10)
2. Spawn Parallel Evaluators
This step needs the Agent tool, which is why oracle no longer binds to the explore agent (explore's own tools list has no Agent/Task) — the skill runs in its forked context with the default full toolset instead. Spawn one explore agent per approach in a SINGLE message:
Agent(explore, "Evaluate [Approach A] against criteria: [criteria list with weights]. Score 1-10 per criterion. Include concrete examples, code samples, and evidence.")
Agent(explore, "Evaluate [Approach B] against criteria: [criteria list with weights]. Score 1-10 per criterion. Include concrete examples, code samples, and evidence.")
Agent(explore, "Evaluate [Approach C] against criteria: [criteria list with weights]. Score 1-10 per criterion. Include concrete examples, code samples, and evidence.")
Each evaluator must return:
- Score (1-10) per criterion with justification
- Concrete code example
- Key risks and mitigations
- Best-case and worst-case scenarios
3. Collect and Score
Build the comparison matrix from evaluator responses.
4. Synthesize Recommendation
Produce the final output in ADR format.
Output Format
Comparison Matrix
## Comparison: [Decision Title]
| Criterion (Weight) | Option A | Option B | Option C |
|-------------------------|----------|----------|----------|
| Performance (25) | 8 (200) | 6 (150) | 7 (175) |
| DX (20) | 9 (180) | 7 (140) | 6 (120) |
| Maintainability (20) | 7 (140) | 8 (160) | 5 (100) |
| Ecosystem (15) | 8 (120) | 9 (135) | 4 (60) |
| Migration Cost (10) | 6 (60) | 8 (80) | 3 (30) |
| Type Safety (10) | 9 (90) | 7 (70) | 8 (80) |
| **TOTAL** | **790** | **735** | **565** |
Score format: raw (weighted) where weighted = raw * weight
When the call is close or taste-heavy, prefer pairwise judgment over absolute scores. Absolute 1–10 scoring drifts and compresses — everything clusters at 6–8, and the "winner" can hinge on one evaluator's mood. Comparative judgment is more reliable: have evaluators judge A-vs-B head-to-head and run a small tournament (each comparison its own call). The weighted matrix above stays right for criteria-driven calls with hard trade-offs; reach for pairwise when the totals land within a few points of each other or the decision is about taste (naming, design, API feel).
This extends the base ADR template from
agents/planner.mdwith scoring matrix and detailed risk sections.
ADR Template
# ADR-NNN: [Decision Title]
## Status
Proposed
## Context
[Why this decision is needed. What problem we're solving.]
## Options Considered
1. **Option A** - [one-line summary]
2. **Option B** - [one-line summary]
3. **Option C** - [one-line summary]
## Decision
We will use **Option A** because [primary reasons].
## Scoring Summary
[Comparison matrix from above]
## Consequences
### Positive
- [benefit 1]
- [benefit 2]
### Negative
- [trade-off 1]
- [trade-off 2]
### Risks
- [risk 1] → Mitigation: [approach]
## References
- [relevant links, docs, benchmarks]
Examples
Example: State Management Selection
User: "Which state management should we use for this Next.js app?"
→ Define criteria (Frontend preset)
→ Agent(explore, "Evaluate Zustand against frontend criteria...")
+ Agent(explore, "Evaluate Jotai against frontend criteria...")
+ Agent(explore, "Evaluate Redux Toolkit against frontend criteria...")
→ Build comparison matrix
→ Output ADR recommendation
Example: Monorepo Tooling
User: "Compare Turborepo vs Nx for our monorepo"
→ Define criteria (Infrastructure preset)
→ Agent(explore, "Evaluate Turborepo...") + Agent(explore, "Evaluate Nx...")
→ Build comparison matrix
→ Output ADR recommendation