Milestone Planning
SkillProductivityBreak a milestone into discrete tasks. Use when starting work on a milestone that has been defined in the project plan.
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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 goalsdocs/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