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improve-system-prompt

v0.1.2

Benchmark and compare system prompt variants (V2/V2a/V2b/V2c) for Sheets Chat by running test scenarios through the real GAS-side ClaudeConversation pipeline. Tests both system-placement and user-placement, then evaluates with heuristic scoring (ABTestHarness) and LLM-as-judge. Product-specific: requires an authorized Sheets Chat/GAS execution integration.

CodexClaude Code1 Skill

By whichguyLicense: MIT0 GitHub starsUpdated 4 days ago

Directory evidence

Runtimes
Codex and Claude Code
Parsed components
1 skill or MCP entry
Source updated
Sep 20, 2026
Manifest status
Canonical path parsed

The directory validates manifest shape and source location. It does not execute the plugin or provide a security endorsement. Review the indexing methodology →

Install improve-system-prompt for Codex and Claude Code

Installs for the current user
codex plugin marketplace add IchenDEV/agent-plugin-mkt
codex plugin marketplace upgrade agent-plugin-marketplace
codex plugin add improve-system-prompt@agent-plugin-marketplace

Paste and run these commands in a terminal with Codex. They add and refresh the PluginsMP catalog, then install this plugin.

The installer fetches third-party code from the source repository shown on this page. This directory validates manifest structure and source location, but does not perform a security audit; review the manifest, components, and source before installing.

Get the source manually
git clone https://github.com/whichguy/skill-craft

Clone the source repository, then follow its setup instructions to add the plugin to a compatible client. The plugin root is plugins/improve-system-prompt/.

Plugin files

plugins/improve-system-prompt/
├── .codex-plugin/plugin.json
├── .claude-plugin/plugin.json
└── skills/improve-system-prompt/SKILL.md

Included Skills1

improve-system-promptskills/improve-system-prompt/SKILL.md

Benchmark and compare system prompt variants (V2/V2a/V2b/V2c) for Sheets Chat by running test scenarios through the real GAS-side ClaudeConversation pipeline. Tests both system-placement and user-placement, then evaluates with heuristic scoring (ABTestHarness) and LLM-as-judge. Product-specific: requires an authorized Sheets Chat/GAS execution integration. **AUTOMATICALLY INVOKE** when: - User says "benchmark system prompts", "compare prompt variants" - User wants to evaluate placement (system vs user message) - User says "which prompt variant is best", "run prompt benchmark" **NOT for:** General prompt engineering, non-GAS prompts, one-off prompt writing. Use an ordinary prompt-editing workflow for editing/refining an active prompt.

Plugin manifests2

plugins/improve-system-prompt/.codex-plugin/plugin.json
{
  "name": "improve-system-prompt",
  "version": "0.1.2",
  "description": "Benchmark and compare system prompt variants (V2/V2a/V2b/V2c) for Sheets Chat by running test scenarios through the real GAS-side ClaudeConversation pipeline. Tests both system-placement and user-placement, then evaluates with heuristic scoring (ABTestHarness) and LLM-as-judge. Product-specific: requires an authorized Sheets Chat/GAS execution integration.",
  "author": {
    "name": "whichguy",
    "url": "https://github.com/whichguy"
  },
  "homepage": "https://github.com/whichguy/skill-craft",
  "repository": "https://github.com/whichguy/skill-craft",
  "license": "MIT",
  "keywords": [
    "skill-craft",
    "improve-system-prompt",
    "portable-skills",
    "prompt-only"
  ],
  "skills": "./skills/",
  "interface": {
    "displayName": "Improve System Prompt",
    "shortDescription": "Benchmark and compare system prompt variants (V2/V2a/V2b/V2c) for Sheets Chat by running test scenarios through the…",
    "longDescription": "Benchmark and compare system prompt variants (V2/V2a/V2b/V2c) for Sheets Chat by running test scenarios through the real GAS-side ClaudeConversation pipeline. Tests both system-placement and user-placement, then evaluates with heuristic scoring (ABTestHarness) and LLM-as-judge. Product-specific: requires an authorized Sheets Chat/GAS execution integration.",
    "developerName": "whichguy",
    "category": "Productivity",
    "capabilities": [
      "Read"
    ],
    "defaultPrompt": [
      "Use $improve-system-prompt:improve-system-prompt for this task."
    ]
  }
}
plugins/improve-system-prompt/.claude-plugin/plugin.json
{
  "name": "improve-system-prompt",
  "version": "0.1.2",
  "description": "Benchmark and compare system prompt variants (V2/V2a/V2b/V2c) for Sheets Chat by running test scenarios through the real GAS-side ClaudeConversation pipeline. Tests both system-placement and user-placement, then evaluates with heuristic scoring (ABTestHarness) and LLM-as-judge. Product-specific: requires an authorized Sheets Chat/GAS execution integration.",
  "author": {
    "name": "whichguy",
    "url": "https://github.com/whichguy"
  },
  "homepage": "https://github.com/whichguy/skill-craft",
  "repository": "https://github.com/whichguy/skill-craft",
  "license": "MIT",
  "keywords": [
    "skill-craft",
    "improve-system-prompt",
    "portable-skills",
    "prompt-only"
  ]
}

For maintainers

If you maintain this plugin, link to this source-backed listing from your README so users can review its manifest and indexed components.

[improve-system-prompt on Agent Plugins Marketplace](https://pluginsmp.com/plugins/improve-system-prompt)