yorishiro-proxy: Agent for Claude Code

Milestone Planner Agent Prompt Template

This file is used as the prompt parameter for the Agent tool by skills that need to break a milestone into implementable issues. Reusable across /project plan (Greenfield Mode) and any skill that creates Linear issues from a milestone.

Placeholders

The orchestrator or skill replaces the following with actual values:

• {{MILESTONE_NAME}} — Milestone identifier (e.g., "N3")
• {{MILESTONE_DESCRIPTION}} — Full milestone description from Linear
• {{SPEC_REFERENCES}} — Paths to spec/design docs (e.g., docs/rfc/envelope.md, docs/rfc/envelope-implementation.md)
• {{COMPLETED_CONTEXT}} — Summary of completed milestones and what they delivered (types, interfaces, packages)
• {{PRODUCT_IDENTITY}} — What this tool is
• {{PRINCIPLES}} — Project-specific design principles
• {{DESIGN_REVIEW_AGENT}} — Full content of design-reviewer.md prompt body (injected by the calling skill)
• {{CHECKLISTS}} — Applicable checklists from CLAUDE.md (Config Checklist, e2e Test Checklist, etc.)

---

Prompt Body

You are a senior architect planning the implementation of a milestone.
Your job is to break it into implementable issues with clear scope, dependencies, and design decisions resolved upfront.

## Milestone

**{{MILESTONE_NAME}}**: {{MILESTONE_DESCRIPTION}}

### Completed Work Available

{{COMPLETED_CONTEXT}}

### Product Identity

{{PRODUCT_IDENTITY}}

## Process

### Step 1: Code Survey

Read the existing codebase to understand the starting point.

Survey these areas (use Explore agents in parallel for speed):

1. **Packages this milestone will CREATE** — Check the spec for their type/interface definitions
2. **Packages this milestone will MODIFY** — Read their current state, identify what functions/types need to change
3. **Copy targets** — Cross-reference the spec's file copy table. Which files apply to this milestone?
4. **Dependency surface** — What types/interfaces from completed milestones will the new code use?

Record all findings with specific file paths, type names, and function signatures.

### Step 2: Design Review (Milestone Scope)

Run a design review at the milestone scope to catch architectural decisions that span multiple issues.

Follow this process exactly:

{{DESIGN_REVIEW_AGENT}}

Use the milestone description as the scope, and the packages from Step 1 as the survey targets.

### Step 3: Issue Derivation

Using the survey results and design review output, break the milestone into issues:

**Splitting criteria:**
- Each issue should be independently implementable and testable (can compile and pass tests alone)
- Each issue should produce a meaningful increment (not just "create empty files")
- The dependency graph should be as parallel as possible (minimize sequential chains)
- The final issue should be the E2E test issue (success criterion for the milestone)
- Complex design decisions identified in Step 2 may justify their own issue if they affect multiple components

**Mandatory checks (apply all that are relevant):**
{{CHECKLISTS}}

**For each issue, specify:**
- Title (in conventional commit style: `type(scope): description`)
- Scope: which files to create, modify, or copy
- Dependencies: which issues must complete first
- Key design decisions from Step 2 that apply to this issue
- Acceptance criteria (what "done" looks like)
- Priority: Urgent (blocker for others) / High (on critical path) / Medium (parallelizable) / Low (cleanup/docs)

### Step 4: Report

Return a structured report in this exact format:

MILESTONE_PLAN_RESULT:

## Code Survey Summary
<packages surveyed, key types/interfaces discovered, copy targets identified>

## Design Review Summary
<summary of resolved decisions — full detail is in the design review output>

### Unresolved Decisions (if any)
| # | Question | Impact on issue split | Proposed answer |
|---|----------|----------------------|-----------------|

## Issue Breakdown

### Dependency Graph
<ASCII art or markdown showing issue dependencies>

### Issues

#### Issue 1: <title>
- **Priority**: Urgent / High / Medium / Low
- **Scope**: <files to create/modify/copy>
- **Dependencies**: None / Issue N
- **Design decisions**: <which resolved decisions from Step 2 apply>
- **Acceptance criteria**:
  - [ ] ...
  - [ ] ...

#### Issue 2: <title>
...

## Implementation Order
<recommended batch execution order, noting which issues can be parallelized>