Approach Evaluation

Purpose / When to Activate

Activate when the invoking agent identifies a technical or architectural decision point where:

• Multiple viable implementation approaches exist and the best choice is non-obvious
• A technology, library, or service is being introduced for the first time in the project
• No established convention exists in conventions.md for the problem domain
• The problem touches a domain with well-known industry standards that should be considered
• A prior approach failed or showed limitations (post-mortem driven re-evaluation)

Do NOT activate when:

• A convention already exists in conventions.md for this exact problem
• The approach is explicitly defined in the Story or a prior decision
• The Story is Tier 1 / MicroDelivery with obvious implementation
• The evaluation would delay delivery without reducing meaningful uncertainty

This skill researches and compares — it does not decide. The invoking agent (Planning Sub-Agent or Discovery Agent) reads the output and makes the decision.

Process

Phase 1 — Problem Framing

1. State the problem precisely: what capability is needed, what constraints apply
2. Read contexts/memory/index.md. Resolve and load:
   • The project category file → extract tech stack, architectural boundaries, known constraints
   • The patterns category file → extract established patterns and conventions
   • The decisions category file → extract prior decisions on related topics Do not assume specific file paths — resolve from index.
3. Define evaluation criteria specific to this problem. Always include:
   • Stack compatibility — does it work with the project's tech stack? (read from project context file, not hardcoded here)
   • Constraint alignment — does it respect the architectural boundaries described in the project context?
   • Operational fit — maintainability given team size and constraints described in project context
   • Maturity — production readiness, community support, documentation quality
4. Add problem-specific criteria as needed (performance, cost, security, scalability, etc.)

Phase 2 — Industry Research

5. Research current industry standards and best practices for the problem:
   • Use web search for current state-of-the-art and community consensus
   • Use Context7 or documentation tools for library/framework specifics
   • Check for established patterns in similar projects or architectures
6. Identify 2-3 viable approaches — not one, not ten
   • Each approach must be genuinely viable (not a strawman)
   • Include the "obvious" approach (what the LLM would default to) even if it may not be best
   • Include at least one alternative that challenges the default
7. For each approach, gather factual evidence:
   • How it works (brief mechanism description)
   • Where it is used successfully (real examples, not hypothetical)
   • Known limitations or failure modes
   • Compatibility with edge compute / serverless environments (if relevant)

Phase 3 — Structured Comparison

8. Evaluate each approach against every criterion from Phase 1
9. Use factual evidence only — no "this feels better" reasoning
10. Flag any criterion where information is uncertain or unavailable
11. Note any approach that would require violating an existing convention or decision

Phase 4 — Trade-off Surfacing

12. For each approach, state explicitly:
    • What you gain by choosing it
    • What you lose or accept as a trade-off
    • What it implies for future decisions (lock-in, reversibility)
13. If one approach is clearly dominated (worse on all criteria), note it but do not eliminate it — the agent decides

Outputs

# Approach Evaluation — {Story ID or Decision Context}: {Problem Title}

## Problem Statement

{What needs to be solved, in one paragraph}

## Evaluation Criteria

| # | Criterion | Weight | Source |
|---|-----------|--------|--------|
| C1 | {criterion} | must-have / important / nice-to-have | {project context reference} |
| C2 | {criterion} | must-have / important / nice-to-have | {project context reference} |

## Approaches Identified

### Approach A — {Name}

**Mechanism:** {how it works — 2-3 sentences}
**Evidence:** {where it's used, maturity signals}
**Limitations:** {known failure modes or constraints}

### Approach B — {Name}

**Mechanism:** {how it works — 2-3 sentences}
**Evidence:** {where it's used, maturity signals}
**Limitations:** {known failure modes or constraints}

### Approach C — {Name} (if applicable)

**Mechanism:** {how it works — 2-3 sentences}
**Evidence:** {where it's used, maturity signals}
**Limitations:** {known failure modes or constraints}

## Comparison Matrix

| Criterion | Approach A | Approach B | Approach C |
|-----------|-----------|-----------|-----------|
| C1: {name} | {factual assessment} | {factual assessment} | {factual assessment} |
| C2: {name} | {factual assessment} | {factual assessment} | {factual assessment} |

## Trade-offs

### Approach A
- **Gains:** {what you get}
- **Costs:** {what you accept}
- **Lock-in:** {reversibility assessment}

### Approach B
- **Gains:** {what you get}
- **Costs:** {what you accept}
- **Lock-in:** {reversibility assessment}

## Open Questions

- {Any criterion where evidence is uncertain or missing}
- {Any constraint that needs human clarification}

## Sources

- {URL or reference for each factual claim}

Saves to contexts/artefacts/evaluations/{id}.approach-evaluation.md.

Quality Checks

• Every criterion has a clear source (project context, not invented)
• Every assessment in the comparison matrix is factual, not opinion
• No approach is dismissed without evidence
• No approach is favored without evidence
• Trade-offs are explicit and symmetric (gains AND costs for each)
• Sources are provided for industry claims
• The evaluation does not contain a recommendation or decision
• Uncertain information is flagged as uncertain, not presented as fact

Non-Goals

This skill must NOT:

• Recommend or decide — the agent decides after reading the evaluation
• Invent criteria not grounded in project context
• Hallucinate library capabilities or industry practices — cite sources
• Evaluate more than 3 approaches (focus drives quality)
• Produce vague assessments ("this is generally good") — every claim must be specific and evidence-backed
• Skip the "obvious" approach — even if the default seems suboptimal, it must be evaluated fairly

The best approach is the one that survives honest comparison — not the one that arrives first.