Consult Opus for Design Decisions

Delegate design decisions to an Opus subagent. Routing criteria (when to use this vs AskUserQuestion) are in the always-loaded design-decisions.md fragment.

Usage Pattern

Step 1: Identify the Decision

Recognize when you're about to use AskUserQuestion for a design/architectural choice:

Examples:

• "Should I structure this as a class or functions?"
• "Which error handling pattern fits better here?"
• "How should I organize these modules?"
• "What's the right abstraction level for this component?"

Step 2: Formulate Context for Opus

Prepare the decision context:

1. Current situation: What are you implementing?
2. The decision: What specific choice needs to be made?
3. Options: What are the 2-4 approaches you're considering?
4. Constraints: What design principles or requirements apply?
5. Codebase context: What existing patterns or files are relevant?

Step 3: Invoke Opus Subagent

Use Task tool to launch an Opus agent with the design question:

Task(
  subagent_type="general-purpose",
  model="opus",
  description="Design decision for [brief description]",
  prompt="You are providing architectural guidance for a design decision.

## Context
[Describe the implementation context]

## Decision Needed
[State the specific question]

## Options Considered
1. [Option A with trade-offs]
2. [Option B with trade-offs]
3. [Option C if applicable]

## Constraints
- [Design principle 1]
- [Design principle 2]
- [Existing pattern: reference to code/docs]

## Your Task
Recommend the best approach and explain your reasoning:
1. Which option best fits the constraints?
2. Why is it superior to the alternatives?
3. Are there any important caveats or implementation notes?

Return a concise recommendation (1-2 paragraphs) that I can immediately act on."
)

Step 4: Execute Recommendation

When Opus returns:

• Read the recommendation
• Apply the guidance immediately
• No need to confirm with user (Opus made the call)
• Document the decision if significant (in code comments or design docs)