Skill: Update Plan

What This Skill Does

Keeps planning artifacts synchronized with actual progress:

• Updates todo items (mark done, add new items, note blockers)
• Updates phase status (pending → in_progress → completed)
• Updates plan status and changelog
• Updates implementation plan if approach changed during work
• Prepares for next phase when current phase completes

When to Use

• During work on a plan phase: to track progress in real-time
• After completing work: to mark items and phases as done
• When blockers are discovered: to document them
• When the implementation approach changes: to update the implementation plan
• When the user asks to "update the plan" or "mark phase as done"

Execution Model (Recommended)

• Preferred: the primary agent runs this skill and updates artifacts under plans/<name>/.
• Rationale: plan updates encode session decisions and current intent; the primary has the best access to that context.
• Use doc-explorer only if verifying acceptance criteria requires codebase analysis (results are written to docs/).
• Optional (edge cases): delegate mechanical edits (bulk todo moves, large reshuffles) to doc-explorer if needed.

Workflow

Step 1: Identify the Plan

Find the active plan:

• Check plans/ directory for existing plans
• If multiple plans exist, use the question tool to ask the user which plan
• Read the plan's plan.md to understand the current status
• Read todo.md to see current task state

Step 2: Determine What to Update

Option A: Todo updates (most common)

• Mark completed items: move from Pending/In Progress to Completed
• Add new items discovered during work
• Mark blocked items with reason
• Move next items to In Progress

Option B: Phase completion

• Verify all acceptance criteria from the phase document are met
• Update phase status in phases/phase-N.md frontmatter
• Update the phases table in plan.md
• Populate todo list with next phase's items (from implementation plan)
• Add changelog entry

Option C: Implementation plan revision

• If the technical approach changed during implementation
• Update the affected implementation/phase-N-impl.md
• Document the reason for the change
• Update any affected todo items

Option D: Plan-level updates

• Requirements changed → update plan.md
• New risks identified → add to risks table
• Scope adjustment → update scope section

Step 3: Apply Updates

Updating Todo List (todo.md)

### Completed
- [x] Implement user authentication endpoint (2025-02-14)

### In Progress
- [ ] Add input validation for login form

### Pending
- [ ] Write integration tests for auth flow

### Blocked
- [ ] Deploy to staging - waiting for CI pipeline fix

Always add a changelog entry:

### 2025-02-14
- Completed: Implement user authentication endpoint
- Started: Add input validation for login form
- Blocked: Deploy to staging (CI pipeline issue)

Updating Phase Status

In phases/phase-N.md frontmatter:

status: completed  # was: in_progress
updated: "2025-02-14"

Updating Plan Changelog

In plan.md:

### 2025-02-14
- Phase 1 completed, Phase 2 started

Step 4: Phase Transition

When a phase is completed and the next phase begins:

1. Mark current phase as completed
2. Mark next phase as in_progress
3. Read the next phase's implementation plan
4. Populate the todo list with the next phase's implementation steps
5. Update the todo list's Phase Context section: update phase/implementation links, relevant docs, and latest handover reference
6. Update plan status in plan.md if needed
7. Add changelog entry documenting the transition

When the final phase is completed (Plan Completion):

1. Mark the final phase as completed
2. Update plan status in plan.md frontmatter to completed
3. Verify that the overall Definition of Done is met
4. Add a final changelog entry: "Plan completed"
5. Clear the todo list's active phase header or add a "Plan Completed" note
6. Use the question tool to confirm with the user that the plan is truly done

Step 5: Report

Summarize what was updated. If the phase is complete, highlight:

• What was achieved
• Whether all acceptance criteria were met
• What comes next

Rules

1. Always read before writing: Read the current state of all affected files before making changes.
2. Changelog is append-only: Never modify or remove existing changelog entries. Only add new entries.
3. Preserve history: When moving todo items between sections, maintain the completion date annotation.
4. Atomic updates: Update all related files together (todo + phase + plan) - don't leave them in an inconsistent state.
5. Phase transitions are explicit: A phase is only completed when all acceptance criteria are verified. Use the question tool to confirm with the user if unsure.
6. Track deviations: If the actual implementation deviated from the plan, document the deviation in the implementation plan rather than silently updating.
7. Use subagents sparingly: Plan updates are typically small enough for the primary agent. Only use subagents if verifying acceptance criteria requires codebase analysis.
8. File-based interface: All updates are written to plan files. Do not return updated content as chat messages.

Templates

This skill includes normative templates as bundled files. Only read the templates when processing them. Output MUST preserve template headings/frontmatter keys when updating plan artifacts:

• tpl-todo.md - Expected structure for the todo list
• tpl-phase.md - Expected structure for phase documents
• tpl-implementation-plan.md - Expected structure for implementation plans
• tpl-plan.md - Expected structure for the plan document (reference for changelog/phases table updates)