Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add StChiotis/Library-First-Engineering --skill lfe-to-prdgit clone --depth 1 https://github.com/StChiotis/Library-First-EngineeringWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/stchiotis/library-first-engineering/lfe-to-prd)<a href="https://agentmods.dev/skills/stchiotis/library-first-engineering/lfe-to-prd"><img src="https://agentmods.dev/badge/skills/stchiotis/library-first-engineering/lfe-to-prd.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00034 | $0.00473 |
| Opus 5 | $0.00017 | $0.00236 |
| Sonnet 5 | $0.00007 | $0.00095 |
| Haiku 4.5 | $0.00003 | $0.00047 |
Grade A, and why
lfe-to-prd scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
LFE To PRD
Position in Pipeline
- Phase: 1 (Architect sub-pipeline, Step 2)
- Persona: Architect
- Input:
.plans/01_grill_summary.md - Output:
.plans/02_prd.md
Process
-
Read input: Read
.plans/01_grill_summary.mdas the source of truth — it carries this step's inputs, not the conversation. -
Explore the repo to understand the current state of the codebase, if you haven't already. Use the project's domain glossary vocabulary throughout the PRD, and respect any ADRs in the area you're touching.
-
Sketch modules: Identify the major modules you will need to build or modify. Actively look for opportunities to extract deep modules that can be tested in isolation. Check with the human that these modules match their expectations.
-
Write the PRD using the template below and save it to
.plans/02_prd.md.
PRD Template
---
phase: architect
step: 2_prd
status: complete
timestamp: <ISO-8601>
source: .plans/01_grill_summary.md
---
## Problem Statement
The problem the user is facing, from the user's perspective.
## Solution
The solution to the problem, from the user's perspective.
## User Stories
1. As an <actor>, I want a <feature>, so that <benefit>
## Implementation Decisions
- Modules that will be built/modified
- Interfaces that will be modified
- Architectural decisions
- Schema changes
- API contracts
Describe modules and interfaces generically; omit specific file paths or code snippets, which may become outdated.
## Testing Decisions
- Which modules will be tested
- What makes a good test (behavior, not implementation)
- Prior art for tests in the codebase
## Out of Scope
What is explicitly NOT part of this work.
Update pipeline_status.md coordination tracker to mark step 02 as ✅.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 8d ago First seen · 65 lines · 34 tokens per session scan A 0d62889f6264
lfe-to-prd is a skill published in the GitHub repository StChiotis/Library-First-Engineering (43 stars, last pushed 1mo ago), licensed MIT. It adds 34 tokens to every session and 473 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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