Milestone Planning

SkillProductivity

Break a milestone into discrete tasks. Use when starting work on a milestone that has been defined in the project plan.

Available today. Use it from your connected AI after setup.

Connect ahel once, and every AI you use reads what you have installed.

Then ask your AI: use the Milestone Planning skill

What this skill tells your AI

The instructions your AI receives, as published by mattolson/agent-sandbox in .agents/skills/plan-milestone/SKILL.md and read by ahel’s review.

Part of the three-tier planning system. See /plan for an overview.

This skill breaks a milestone into discrete, implementable tasks. The output is a milestone plan that sequences work and identifies dependencies.

Inputs

Before starting, read:

  • docs/plan/project.md - to understand the milestone's context and goals
  • docs/plan/learnings.md - to incorporate lessons from previous work
  • Any relevant decision documents in docs/plan/decisions/

Output

The final artifact is docs/plan/milestones/{milestone}/milestone.md.

The milestone plan can be updated as work progresses. When task scope changes significantly, update the task definition but also record the change in a Changes section. This preserves history for milestone retrospectives while keeping the plan current.

Process

Work through these phases interactively. Each phase should be a conversation.

Phase 1: Context Review

Review the milestone's definition from the project plan.

  • What is this milestone's goal?
  • What are its boundaries (what's in scope, what's not)?
  • What dependencies does it have on prior milestones?
  • What does completion look like?

Confirm understanding before proceeding.

Phase 2: Learnings Review

Review accumulated learnings that may apply to this milestone.

  • What lessons from previous work are relevant here?
  • Are there process improvements to apply?
  • Are there technical pitfalls to avoid?

Note applicable learnings in the milestone plan.

Phase 3: Task Identification

Identify the discrete pieces of work.

  • What are the logical units of work?
  • Is each task appropriately scoped for a single PR?
  • Are tasks independently testable or verifiable?
  • What are the natural boundaries between tasks?

A task should map to a well-crafted PR: a piece of functionality or a fix, along with relevant tests, sized appropriately for human peer review. Not so large that review becomes burdensome, not so small that it lacks meaningful context.

Phase 4: Dependency Mapping

Understand how tasks relate to each other.

  • Which tasks block other tasks?
  • Which tasks can be done in parallel?
  • Are there external dependencies (APIs, other teams, etc.)?
  • What is the critical path?

Phase 5: Risk Identification

Flag uncertainties specific to this milestone.

  • Which tasks have technical unknowns?
  • Where might scope be unclear?
  • What could cause rework?
  • Are there tasks that should be spiked first?

Phase 6: Sequencing

Order the tasks for execution.

  • What is the recommended order?
  • Where are there decision points that might change the sequence?
  • Which tasks should be done early to reduce risk?

Milestone Plan Template

When all phases are complete, compile into docs/plan/milestones/{milestone}/milestone.md:

# Milestone: {identifier} - {name}

## Goal

{What this milestone achieves}

## Scope

{What's included and explicitly excluded}

## Applicable Learnings

{Lessons from previous work that apply here}

## Tasks

### {m1.1-task-name}

**Summary:** {One-sentence description of what this task delivers}

**Scope:**
- {What's included}
- {What's explicitly excluded or deferred}

**Acceptance Criteria:**
- {Condition that must be true when complete}
- {Another condition}

**Dependencies:** {What must be done first}

**Risks:** {Uncertainties or concerns}

### {m1.2-task-name}

**Summary:** {One-sentence description of what this task delivers}

**Scope:**
- {What's included}
- {What's explicitly excluded or deferred}

**Acceptance Criteria:**
- {Condition that must be true when complete}
- {Another condition}

**Dependencies:** {What must be done first}

**Risks:** {Uncertainties or concerns}

{Continue for all tasks}

## Execution Order

{Recommended sequence, noting parallelization opportunities and decision points}

## Risks

{Milestone-level risks and mitigation strategies}

## Definition of Done

{How we know this milestone is complete}

## Changes

{Record significant changes to scope or tasks as they occur}

### {Date}: {Change summary}

{What changed and why}

Signals

GitHub stars
205
Forks
19
Last commit
Sep 2026
Advanced
Catalog kind
skill
Gateway key
plan-milestone
Source
github.com/mattolson/agent-sandbox