decision

name	decision
description	Document an architecture or design decision
argument-hint	[topic or existing ID]
disable-model-invocation	true

Decision Documentation Workflow

Document an architecture decision (ADR) or design pattern (DES).

Input

$ARGUMENTS - Optional: topic to document or existing decision ID to update

Context

You must load the following skills and read the following files before proceeding.

Skills

• katachi:framework-core - Workflow principles and decision type guidance

Feature documentation

• docs/feature-specs/README.md - Feature capability index
• docs/feature-designs/README.md - Feature design index
• Read specific feature-specs/ and feature-designs/ docs to understand affected features

Decision indexes

• docs/architecture/README.md - Architecture decisions (ADRs)
• docs/design/README.md - Design patterns (DES)

Reference Guides

• ${CLAUDE_PLUGIN_ROOT}/skills/framework-core/references/code-examples.md - Code snippet guidance (especially for DES)
• ${CLAUDE_PLUGIN_ROOT}/skills/framework-core/references/technical-diagrams.md - Technical diagram guidance (if diagrams help)

Process

1. Determine Decision Type

Ask user what they want to document:

"What kind of decision are you documenting?

A) Architecture Decision (ADR)
   - Hard-to-change technical choices
   - Technology selections, patterns, approaches
   - One-time decisions with significant consequences

B) Design Pattern (DES)
   - Repeatable patterns across the codebase
   - Conventions, coding patterns, cross-cutting concerns
   - Patterns that should be consistent

Which type fits your decision?"

2. Understand the Decision

Ask about the decision:

• What problem led to this decision?
• What approach did you choose?
• What alternatives were considered?
• What are the consequences?

For DES, also ask:

• Where is this pattern used?
• When should it be applied?
• What are the exceptions?

3. Research if Needed

If user is uncertain about alternatives or consequences:

• Use Task tool to research options
• Synthesize findings
• Present alternatives with trade-offs

4. Draft Document

Create complete document following appropriate template.

For ADR:

• Context
• Decision
• Consequences (positive and negative)
• Alternatives considered

For DES:

• Pattern description
• Rationale
• Examples (do this, don't do this)
• Exceptions

5. Validate Classification (Silent)

Dispatch decision-reviewer to validate the classification:

Task(
    subagent_type="katachi:decision-reviewer",
    prompt=f"""
Validate this decision document classification.

## Decision Type
{adr_or_des}

## Draft Document
{draft_content}

## User's Context
{user_context}

## Existing ADR Index
{adr_index}

## Existing DES Index
{des_index}
"""
)

Apply feedback:

• If classification is incorrect, adjust document type
• If decision overlaps with existing, consider updating instead of creating new
• If decision is too trivial, suggest keeping in feature-design only

6. Present for Review

Show draft document to user. Highlight any uncertainties or validation feedback. Ask: "What needs adjustment?"

7. Iterate Based on Feedback

Apply user corrections. Repeat until approved.

8. Assign ID

Determine next available ID:

• For ADR: Check existing ADRs in docs/architecture/
• For DES: Check existing DES in docs/design/

9. Update Index

Add to appropriate README index:

For ADR in docs/architecture/README.md:

• Add to ADR table
• Update quick reference if applicable
• Note affected areas

For DES in docs/design/README.md:

• Add to DES table
• Update quick reference if applicable
• Note when to use

10. Save Document

Write to appropriate location:

• ADR: docs/architecture/ADR-NNN-title.md
• DES: docs/design/DES-NNN-pattern-name.md

11. Identify Affected Features

Ask:

"Which features are affected by this decision?

I'll update their design documents to reference this [ADR/DES]."

List affected features and update their designs to include decision references:

• Add reference in "Key Decisions" section
• Update "Related Decisions" if present
• Ensure design rationale reflects the decision

Workflow

This is a collaborative process:

• Determine type (ADR vs DES)
• Understand the decision
• Research alternatives if needed
• Draft document
• Validate classification with decision-reviewer agent
• Present and iterate with user
• Save and update index
• Identify affected features