gen-evals

gen-evals is a command for Claude Code from avelikiy/great_cto. It costs 30 tokens per session (1,571 once invoked), scanned A, original, MIT.

A command that creates Markdown evaluation cases for an agent by reading its prompt and saving test files in the project's evaluation folder.

In plain words
What is it for?
Use it to generate synthetic test cases for checking whether an agent follows its intended behavior.
Why use it?
It removes the manual work of turning an agent's instructions into repeatable tests.

Command for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: model in frontmatter; reads .claude/ paths.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the great-cto plugin — 40 skills, 44 commands, 70 agents shipped together

Good fit Use it to generate synthetic test cases for checking whether an agent follows its intended behavior.

Compare 6 commands from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add avelikiy/great_cto
Claude Code
/plugin install great-cto

Made for: Claude Code.

Or install great-cto, the plugin that ships this one along with the rest of its 40 skills, 44 commands, 70 agents.

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 gen-evals

README.md
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Your own site
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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.

agentmods 80×15 button for gen-evals

Your own site · 80×15
<a href="https://agentmods.dev/commands/avelikiy/great_cto/gen-evals"><img src="https://agentmods.dev/badge/commands/avelikiy/great_cto/gen-evals.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 30 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,571 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 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 5.1 $0.00030 $0.01571
Opus 5 $0.00015 $0.00785
Sonnet 5 $0.00006 $0.00314
Haiku 4.5 $0.00003 $0.00157

Measured 2d ago against content hash 726d63c9ce30, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

gen-evals 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 2d 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.

commands/gen-evals.md · 146 lines

How it starts

The opening of the file, as written. The whole thing — 146 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are the great_cto /gen-evals command. You generate synthetic evaluation test cases for a named agent, saving them in the established tests/eval/EVAL-*.md format. This is the Sprint 2 implementation of the self-evolution pattern: synthetic eval dataset generation from agent documentation.

Step 1 — Parse arguments and locate agent

AGENT_NAME="${ARGUMENTS%% *}"  # first word
COUNT=$(echo "$ARGUMENTS" | grep -oE '\-\-count [0-9]+' | grep -oE '[0-9]+' || echo 20)
[ -z "$AGENT_NAME" ] && echo "Usage: /gen-evals <agent-name> [--count N]" && exit 1

# Locate agent file in plugin dir or repo
PLUGIN_DIR=${CLAUDE_PLUGIN_ROOT:-$(ls -d ~/.claude/plugins/cache/*/great_cto/*/ 2>/dev/null | sort -V | tail -1 | sed 's|/$||')}
AGENT_FILE="${PLUGIN_DIR}/agents/${AGENT_NAME}.md"
[ ! -f "$AGENT_FILE" ] && AGENT_FILE="agents/${AGENT_NAME}.md"
[ ! -f "$AGENT_FILE" ] && echo "ERROR: agent not found: ${AGENT_NAME}" && exit 1

echo "Generating $COUNT eval cases for: $AGENT_NAME"
echo "Reading: $AGENT_FILE"

Step 2 — Read agent definition

Read the full agent file. Focus on:

  • What the agent is supposed to do (description, step-by-step instructions)
  • What it must NOT do (constraints, rejection criteria, anti-patterns)
  • What evidence / artifacts it must produce (output format, required fields)
  • The domain it covers (archetype, compliance area, specialisation)

This is the source material for generating realistic test cases.

Step 3 — Generate test cases (LLM synthesis)

Based on the agent definition, generate $COUNT realistic, adversarial test cases.

For each test case, produce:

| # | Input / Scenario | Expected behaviour | Pass criterion |

Generation rules (from the PLAN.md pattern):

  • Split 60% routine / 40% adversarial (edge cases, subtle failure modes)
  • Routine: valid inputs where the agent should succeed clearly
  • Adversarial: inputs designed to expose the most common failure modes for this agent type
  • Expected behaviour: rubric-based, not exact-match (e.g. "flags at least 2 injection vectors" not "outputs the word SQL")
  • Pass criterion: objectively verifiable — a judge model can determine pass/fail

Read the full file on GitHub · 146 lines

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. 2d ago Changed 726d63c9ce30
  2. 6d ago First seen · 146 lines · 30 tokens per session scan A b47fae2a7ee9

Subscribe to this mod's changes

gen-evals is a command published in the GitHub repository avelikiy/great_cto (89 stars, last pushed yesterday), licensed MIT. It adds 30 tokens to every session and 1,571 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 2026-09-03.