What is prompt-validation?

A scorecard for evaluating Claude prompts and system prompts. It rates them across six dimensions using anchored scores from 1 to 5, then helps identify ways to improve them.

Use it to review, score, diagnose, and improve prompts, including prompts that define an assistant's overall behaviour.

It makes prompt review more consistent than relying on intuition alone. It helps explain why an instruction may produce poor or unreliable results.

prompt-validation — Skill for Claude Code by drayline/rootnode-skills

Install

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.

Any agent

npx skills add drayline/rootnode-skills --skill prompt-validation

Clone the repo

git clone --depth 1 https://github.com/drayline/rootnode-skills

Made for: Claude Code.

Or install rootnode-prompts, the plugin that ships this one along with the rest of its 11 skills.

Wrote 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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/drayline/rootnode-skills/prompt-validation/github.svg)](https://agentmods.dev/skills/drayline/rootnode-skills/prompt-validation)

Your own site

<a href="https://agentmods.dev/skills/drayline/rootnode-skills/prompt-validation"><img src="https://agentmods.dev/badge/skills/drayline/rootnode-skills/prompt-validation/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/drayline/rootnode-skills/prompt-validation"><img src="https://agentmods.dev/badge/skills/drayline/rootnode-skills/prompt-validation.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 193 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 4,551 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin unknown No closer match found in the catalogue.

Token cost

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	$0.00193	$0.04551
Opus 5.5	$0.00077	$0.01820
Sonnet 5.5	$0.00039	$0.00910
Haiku 4.5	$0.00019	$0.00455

Measured 3d ago against content hash 66dad57e0a29, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

prompt-validation 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 3d 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.

plugins/rootnode-prompts/skills/prompt-validation/SKILL.md · 264 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

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.

3d ago Changed · +1 lines 66dad57e0a29
4d ago First seen · 263 lines · 193 tokens per session scan A 173bebf6b6b9

Subscribe to this mod's changes

prompt-validation is a skill published in the GitHub repository drayline/rootnode-skills (40 stars, last pushed 4d ago), with no licence file. It adds 193 tokens to every session and 4,551 once invoked, about $0.0008 per session on Opus 5.5. 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 2026-11-03.

Building agents Claude Code agent-skills ai-tools anthropic awesome-claude-prompts claude-ai

prompt-validation next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
prompt-validationdrayline/rootnode-skills	Skill	40	4d ago	none	A	193	Claude Code
microservices-architecturetravisjneuman/.claude	Skill	107	2d ago	MIT	A	30	Claude Code, Codex
accessibility-a11ytravisjneuman/.claude	Skill	107	2d ago	MIT	A	26	Claude Code, Codex
ai-ml-developmenttravisjneuman/.claude	Skill	107	2d ago	MIT	A	43	Claude Code, Codex
android-developmenttravisjneuman/.claude	Skill	107	2d ago	MIT	A	33	Claude Code, Codex
audio-productiontravisjneuman/.claude	Skill	107	2d ago	MIT	A	33	Claude Code, Codex
authentication-patternstravisjneuman/.claude	Skill	107	2d ago	MIT	A	28	Claude Code, Codex