Skip to content
🧪

Prompt Engineer

Build evals, A/B test prompts, audit skills, and benchmark LLM outputs at production quality

Install onClaude Cowork
Made by The AI Career Lab
4 commands, 2 skills

The Prompt Engineer plugin helps you ship prompts and skills that survive production. Every command works standalone with your input — describe the prompt, skill, or eval scenario and get a structured draft ready for your review.

Use /eval-rubric to build a custom evaluation rubric for a skill or prompt covering accuracy, tone, compliance, and latency. Use /test-batch to run a prompt against 10–100 synthetic test cases and produce a coverage and quality report. Use /skill-version to version-control a skill, A/B test two variants, and output a statistical-significance verdict. Use /skill-audit to run static analysis on a SKILL.md — checking frontmatter, edge cases, prompt-injection surface, and length budget.

The plugin's skills activate automatically when relevant: Prompt Optimization Loop covers test case design, edge cases, adversarial inputs, and iteration based on eval results, plus Skill Benchmarking measures latency, accuracy, token cost, and token-budget compliance across skill variants.

Commands

/eval-rubric

Build a custom evaluation rubric for a skill or prompt covering accuracy, tone, compliance, and latency

/test-batch

Run a prompt against 10–100 synthetic test cases and produce a coverage and quality report

/skill-version

Version-control a skill, A/B test two variants, and output a statistical-significance verdict

/skill-audit

Static analysis of SKILL.md — checks frontmatter, edge cases, prompt-injection surface, and length budget

Skills

Skills activate automatically when Claude Cowork detects you're working on relevant tasks — no slash command needed.

Prompt Optimization Loop

Test case design, edge cases, adversarial inputs, and iteration based on eval results

Skill Benchmarking

Latency, accuracy, token cost, and token-budget compliance measurement across skill variants

Usage examples

/eval-rubric Build a rubric for a customer-support triage skill covering accuracy, empathy, no-refund-promises compliance, and latency

/test-batch Generate 50 synthetic cases for /draft-cold-email mixing happy path, edge cases, and prompt-injection adversarial inputs

/skill-version A/B test variant A (prod) vs variant B (draft) on a 40-case eval set with paired bootstrap; output verdict and effect size

/skill-audit Audit this SKILL.md for frontmatter completeness, prompt-injection surface, edge cases, and 2000-token budget compliance

AI Prompts

AI Career Lab — All AI Prompts Bundle

$49one-time

All eight profession-specific AI Prompts packs — 393 agentic skills total with ambient compliance guards. Runs on Claude Cowork.

Get all 8 packs for $49

Install this plugin

Claude Cowork

/plugin marketplace add alexclowe/awesome-claude-cowork-plugins/plugin install prompt-engineer@awesome-claude-cowork-plugins

Paste in Claude Cowork (requires a paid Claude plan). Add the marketplace once, then install any plugin by name.

All content generated by this plugin is for drafting and informational purposes only. The prompt engineer is responsible for reviewing, verifying, and customizing all outputs before professional use. This plugin does not constitute professional advice.