cpv-semantic-validation-skill

cpv-semantic-validation-skill is a skill for Claude Code, Codex from Emasoft/claude-plugins-validation. It costs 50 tokens per session (1,250 once invoked), scanned A, original, MIT.

A review tool for checking whether skills and agents are clearly described, trigger at the right time, and contain subtle safety problems.

In plain words
What is it for?
Use it to perform a deep semantic review of a skill or agent and produce a quality grade and report.
Why use it?
It finds ambiguous instructions and hidden issues that simple structural checks may miss.

Skill for Claude CodeCodex

Part of the claude-plugins-validation plugin — 52 skills, 14 commands, 14 agents, 10 plugins shipped together

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.

agentmods
npx agentmods add skills/emasoft/claude-plugins-validation/cpv-semantic-validation-skill
Any agent
npx skills add Emasoft/claude-plugins-validation --skill cpv-semantic-validation-skill
Clone the repo
git clone --depth 1 https://github.com/Emasoft/claude-plugins-validation

Made for: Claude Code, Codex.

Or install claude-plugins-validation, the plugin that ships this one along with the rest of its 52 skills, 14 commands, 14 agents, 10 plugins.

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.

agentmods badge for cpv-semantic-validation-skill

README.md
[![agentmods](https://agentmods.dev/badge/skills/emasoft/claude-plugins-validation/cpv-semantic-validation-skill.svg)](https://agentmods.dev/skills/emasoft/claude-plugins-validation/cpv-semantic-validation-skill)
Your own site
<a href="https://agentmods.dev/skills/emasoft/claude-plugins-validation/cpv-semantic-validation-skill"><img src="https://agentmods.dev/badge/skills/emasoft/claude-plugins-validation/cpv-semantic-validation-skill.svg" alt="Measured on agentmods" height="20"></a>
Per session 50 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,250 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original 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.

ModelPer sessionOnce invoked
Fable 5 $0.00050 $0.01250
Opus 5 $0.00025 $0.00625
Sonnet 5 $0.00010 $0.00250
Haiku 4.5 $0.00005 $0.00125

Measured yesterday against content hash 2c5a07002446, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

cpv-semantic-validation-skill 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 yesterday.

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.

skills/cpv-semantic-validation-skill/SKILL.md · 126 lines

How it starts

The opening of the file, as written. The whole thing — 126 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Semantic Validation Skill

Deep AI analysis. Opus 1M, ~10-50× tokens of script validation.

Overview

7 quality pillars + 3 conditional security pillars → Semantic Grade (A-F).

HARD SEPARATION — USER CHOICE. Programmatic (/cpv-validate-plugin, 0 tokens) catches 95%+ via regex and surfaces CANDIDATES via INFO — never escalates. Semantic (this skill, opt-in via /cpv-semantic-validation, thousands–millions tokens) handles the 5% residue: ambiguous injection, shadow features, subtle MCP-description injection. Most projects publish-ready with programmatic alone. Never default-on.

Prerequisites

  • Python 3.12+ with pyyaml, uv package manager, target skill/agent path

Instructions

  1. Run baseline via launcher (alias skill) — see references/launcher-invocation.md. Direct invocation refused.

    The one-liner · Why the launcher is mandatory · Direct invocation (development only)

  2. Read SKILL.md / agent .md
  3. Evaluate 7 pillars + applicable conditional security pillars
  4. Write report → $MAIN_ROOT/reports/cpv-semantic-validator-agent/<YYYYMMDD_HHMMSS±HHMM>-<slug>.md
  5. Return [DONE] Grade: X. Report: <filepath>

Output

  • Grade: A-F. Criteria: Pass/Partial/Fail per pillar. Report: $MAIN_ROOT/reports/cpv-semantic-validator-agent/<ts±tz>-<slug>.md. Both reports/ and reports_dev/ gitignored.

Error Handling

  • If script validation fails CRITICAL → semantic skipped. Fix structure first.
  • Invalid path → report error, exit.

Examples

/cpv-semantic-validation ./skills/my-skill/
/cpv-semantic-validation ./agents/my-agent.md

Token Optimization

Opt-in only. Baseline first. Write report to disk; return grade + filepath.

Conditional Pillar: Channel MCP Server Source-Code Security

Runs only when plugin.json.channels is non-empty AND plugin ships MCP server source.

Load channel-source-security:

  • Why This Pillar Exists
  • Scope
  • Source-Language Support
  • Deterministic Prefilter Helper
  • Rule 1 — Inbound Sender Gating (CRITICAL)
  • Rule 2 — Permission-Relay Capability Gate (CRITICAL)
  • Rule 3 — Room/Chat-ID-Only Gating (MAJOR)
  • Rule 4 — PASSED
  • Opus Prompt Template
  • Integration With the A-F Rubric
  • Report Format

Read the full file on GitHub · 126 lines

Files

What ships with it

7 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.

  1. yesterday First seen · 126 lines · 50 tokens per session scan A 2c5a07002446

Subscribe to this mod's changes

cpv-semantic-validation-skill is a skill published in the GitHub repository Emasoft/claude-plugins-validation (4 stars, last pushed 2d ago), licensed MIT. It adds 50 tokens to every session and 1,250 once invoked, about $0.0003 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 2026-09-03.