/brief

name: brief
description: Interactive briefing of a plan file — explains reasoning, schema decisions, component choices. Use when developers need to understand a plan before approving.
effort: low
argument-hint: "[path to plan file]"

Plan Briefing

Interactive walkthrough of a plan's reasoning, decisions, and solution shape. Designed for developers who need to understand a plan in 1-2 minutes instead of reading the full document.

Why This Exists

Plans answer "what to do" but bury "why." This skill bridges that gap with an interactive walkthrough.

Usage

/phx:brief                                    # Latest plan
/phx:brief .claude/plans/user-auth/plan.md    # Specific plan

Arguments

• `$ARGUMENTS` = Path to plan file (optional, auto-detects latest)

Mode Detection

Read the plan file and determine mode from phase statuses:

• **All phases `[PENDING]`** = Pre-work briefing (what WILL happen)
• **Any phase `[COMPLETED]` or `[IN_PROGRESS]`** = Post-work briefing

(what WAS done and why)

Execution Flow

Step 1: Locate and Load Plan

1. If `$ARGUMENTS` has a path, use it 2. Otherwise, find latest plan:

Use Glob to find `.claude/plans/*/plan.md` and pick the most recent.

3. If no plan found, tell user and suggest `/phx:plan` 4. Read the plan file

Step 2: Load Supporting Artifacts

Read what's available (don't fail if missing):

• `.claude/plans/{slug}/summaries/consolidated.md` (research summary)
• `.claude/plans/{slug}/scratchpad.md` (decisions, dead-ends)
• `.claude/plans/{slug}/progress.md` (work log, post-work only)

Step 3: Present Briefing Sections

Present ONE section at a time, wrapped in the visual briefing block (see `${CLAUDE_SKILL_DIR}/references/briefing-guide.md` Visual Formatting).

**The section MUST be emitted as visible response text BEFORE the `AskUserQuestion` call.** Content composed only in thinking/reasoning is invisible to the user, and the `question` field is too short to carry it. If the user would see only a "Continue?" dialog, the section was never shown. Write the ★ Briefing block as normal output first, then ask:

• If sections remain: question "Continue the briefing?" with options

**"Next: {title}"**, **"Ask me a question about this"**, **"Stop here"**

• If final section: no question needed, show closing message

Section Flow (Pre-Work Mode)

| # | Title | Source | |---|-------|--------| | 1 | What We're Building | Summary + Scope | | 2 | Key Decisions | Technical Decisions + scratchpad rationale | | 3 | Solution Shape | Phases overview + Data Model | | 4 | Risks & Confidence | Risks table + unknowns/spikes |

Section Flow (Post-Work Mode)

| # | Title | Source | |---|-------|--------| | 1 | What Was Built | Summary + completion status | | 2 | Key Decisions & Why | Technical Decisions + scratchpad | | 3 | How It Was Built | Phases with implementation notes | | 4 | Lessons & Patterns | Risks encountered + patterns used |

See `${CLAUDE_SKILL_DIR}/references/briefing-guide.md` for section content templates.

Iron Laws

1. **ONE section at a time** — never dump all content 2. **User controls pace** — always offer to stop 3. **Explain WHY, not just WHAT** — rationale over listing 4. **Ground in artifacts** — focus on insights specific to this plan's research, decisions, and scratchpad entries, not general programming concepts 5. **Keep each section under 20 lines** — this is a briefing, not a lecture 6. **NEVER skip sections or auto-start work** — briefing is read-only; do not execute plan tasks or launch `/phx:work` without explicit user request 7. **SECTION TEXT BEFORE THE QUESTION** — every ★ Briefing block is visible response text emitted before its `AskUserQuestion`; never deliver a section only inside thinking or the question field

Closing Message

After final section (or when user stops):

That's the briefing! For full details, see:
{plan_path}

Ready to proceed? Try `/phx:work {plan_path}` to start execution.

Post-work variant:

That's what was built! For full details, see:
{plan_path}

Consider `/phx:compound` to capture key learnings for future reference.

Integration

/phx:plan  -->  /phx:brief (optional)  -->  /phx:work  -->  /phx:brief (optional)
  create       understand before            execute        understand after

Complex Plan Enhancement

For plans with 5+ phases or 4+ key decisions, consider suggesting visual rendering after Section 3. See `${CLAUDE_SKILL_DIR}/references/visual-explainer.md` for thresholds and commands.

Notes

• Runs in main conversation context (not a subagent)
• Model: no special requirement — uses default session model
• No artifacts written — briefing is ephemeral, plan IS the artifact
• Reference file readable since skill runs in user's session