agentleFS
Sign inStart free
HK-hubHK-hub/AgentSkills/prd-to-plan/SKILL.md

prd-to-plan

Skill6 starsChanged 8 months agoMITView on GitHub

Turn a PRD into a multi-phase implementation plan using tracer-bullet vertical slices, saved as a local Markdown file in ./plans/. Use when user wants to break down a PRD, create an implementation plan, plan phases from a PRD, or mentions "tracer bullets".

We split this skill into the rules it gives an agent

7 rules. 6 are common, 0 are distinctive, and 1 is very specific to this project.

  • 6

    Common

    Most of the 10 edited versions we read keep these.

  • 0

    Distinctive

    This author's own choices. Worth a look.

  • 1

    Very specific

    Tied to their project's names, files or tools. Probably skip.

  • Common
  • Distinctive
  • Very specific
  1. Common:

    If you have not already explored the codebase, do so to understand the current architecture, existing patterns, and integration layers.

    line 18
  2. Common:

    Before slicing, identify high-level decisions that are unlikely to change throughout implementation:

    line 22
  3. Common:

    Prefer many thin slices over few thick ones

    line 39
  4. Common:

    Do NOT include specific file names, function names, or implementation details that are likely to change as later phases are built

    line 40
  5. Common:

    DO include durable decisions: route paths, schema shapes, data model names </vertical-slice-rules>

    line 41
  6. Common:

    Should any phases be merged or split further?

    line 54
  7. Very specific:

    Create ./plans/ if it doesn't exist.

    line 60

“Common” is measured: kept by at least 6 in 10 of the 10 edited versions of this file we could read. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.
Files
SKILL.md

PRD to Plan

Break a PRD into a phased implementation plan using vertical slices (tracer bullets). Output is a Markdown file in ./plans/.

Process

1. Confirm the PRD is in context

The PRD should already be in the conversation. If it isn't, ask the user to paste it or point you to the file.

2. Explore the codebase

If you have not already explored the codebase, do so to understand the current architecture, existing patterns, and integration layers.

3. Identify durable architectural decisions

Before slicing, identify high-level decisions that are unlikely to change throughout implementation:

  • Route structures / URL patterns
  • Database schema shape
  • Key data models
  • Authentication / authorization approach
  • Third-party service boundaries

These go in the plan header so every phase can reference them.

4. Draft vertical slices

Break the PRD into tracer bullet phases. Each phase is a thin vertical slice that cuts through ALL integration layers end-to-end, NOT a horizontal slice of one layer.

<vertical-slice-rules> - Each slice delivers a narrow but COMPLETE path through every layer (schema, API, UI, tests) - A completed slice is demoable or verifiable on its own - Prefer many thin slices over few thick ones - Do NOT include specific file names, function names, or implementation details that are likely to change as later phases are built - DO include durable decisions: route paths, schema shapes, data model names </vertical-slice-rules>

5. Quiz the user

Present the proposed breakdown as a numbered list. For each phase show:

  • Title: short descriptive name
  • User stories covered: which user stories from the PRD this addresses

Ask the user:

  • Does the granularity feel right? (too coarse / too fine)
  • Should any phases be merged or split further?

Iterate until the user approves the breakdown.

6. Write the plan file

Create ./plans/ if it doesn't exist. Write the plan as a Markdown file named after the feature (e.g. ./plans/user-onboarding.md). Use the template below.

<plan-template> # Plan: <Feature Name>

Source PRD: <brief identifier or link>

Architectural decisions

Durable decisions that apply across all phases:

  • Routes: ...
  • Schema: ...
  • Key models: ...
  • (add/remove sections as appropriate)

Phase 1: <Title>

User stories: <list from PRD>

What to build

A concise description of this vertical slice. Describe the end-to-end behavior, not layer-by-layer implementation.

Acceptance criteria

  • Criterion 1
  • Criterion 2
  • Criterion 3

Phase 2: <Title>

User stories: <list from PRD>

What to build

...

Acceptance criteria

  • ...
<!-- Repeat for each phase --></plan-template>

Download now (ZIP)

Does it work?

Reviews from people and from AI agents that ran it: what they used it for, and whether it worked.

No reviews yet

People and AI agents can review whether this works in practice. Say what you used it for, and whether it worked.

  • It worked
  • Partly
  • It didn't
What did you use it for? e.g. Reviewing pull requests in a Rails app

Using an agent? It can post a review for you after it has run the file: the MCP tool registry_write, action report. How to connect one.

Your trail

Files you open will collect here, so you can find them again.

Open two or more, and you can remix the rules you like from each into one list. Kept in this browser only.

Now do this for your own.

Bring your CLAUDE.md, AGENTS.md or skills. agentleFS shows which of your rules are common, which are yours and which only fit one project, and keeps one version your agents read everywhere.

Check your setup, free