agentv-eval-writer

A tool for creating, editing, reviewing, and checking AgentV EVAL.yaml files, which define how an AI system is tested.

In plain words
What is it for?
Writing or updating evaluation suites, adding test cases, configuring rubric or script graders, reviewing eval completeness, and converting between EVAL.yaml and evals.json.
Why use it?
It helps keep test cases, prompts, data, assertions, providers, graders, and run settings in a valid, portable format.

Skill for Claude CodeCodex

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/entityprocess/agentv/agentv-eval-writer
Any agent
npx skills add EntityProcess/agentv --skill agentv-eval-writer
Clone the repo
git clone --depth 1 https://github.com/EntityProcess/agentv

Made for: Claude Code, Codex.

Per session 129 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 8,818 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 $0.00129 $0.08818
Opus 5 $0.00064 $0.04409
Sonnet 5 $0.00026 $0.01764
Haiku 4.5 $0.00013 $0.00882

Measured yesterday against content hash 6a0fc8b46380, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

agentv-eval-writer 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-data/agentv-eval-writer/SKILL.md · 975 lines

How it starts

The opening of the file, as written. The whole thing — 975 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AgentV Eval Writer

Comprehensive docs: https://agentv.dev Promptfoo parity matrix: https://agentv.dev/docs/reference/promptfoo-parity/

Authoring Principle

Treat YAML as the canonical portable model. Prefer authoring .eval.yaml / EVAL.yaml first, then use TypeScript helpers, Python scripts, or executable graders only when they lower to the same fields or when the evaluation logic must actually run code.

Eval files define what is tested and how it runs: prompts, datasets, assertions, task fixtures, top-level providers, and suite run controls. Use field-local file refs such as tests: file://..., prompts: file://..., default_test: file://..., and environment: file://.... String-valued tests and string entries inside tests[] are raw-case refs for direct paths, directories, and globs. Run several full eval suites directly with CLI multi-file selection and tags. Use scoped run: on individual tests only for threshold, repeat, timeout_seconds, and legacy budget_usd; keep provider selection at top-level providers or CLI --provider, put suite budget caps under evaluate_options.budget_usd, authored concurrency under evaluate_options.max_concurrency, suite repeat policy under evaluate_options.repeat, coding-agent testbed setup under environment, provider environment overrides under env, and lifecycle hooks under extensions.

Use @agentv/sdk for TypeScript helper imports. Do not use @agentv/eval for new evals, examples, scaffolds, or skill guidance; it was a deprecated compatibility package and has been removed from this repository.

Authoring Checklist

  • Put grading criteria in assert, not in test-level criteria. Plain assertion strings become an llm-rubric grader.
  • Prefer plain assertion strings for semantic checks when the default rubric grader can judge them. Use type: llm-rubric for structured criteria, custom prompts, custom grader providers, or assertion-level transforms. Use type: agent-rubric when the grader itself must be an agent-capable provider that can inspect the workspace. Use type: script when grading must execute code.
  • Put reference answers in tests[].vars.expected_output or default_test.vars.expected_output, and consume them with an explicit assertion such as type: llm-rubric with value: "Matches the reference answer: {{ expected_output }}". Do not write criteria, scoring instructions, or "the agent should..." rubric prose as the reference answer.
  • For historical or repo-state evals, materialize the repo through a pinned environment setup recipe. Mentioning a SHA only in prompt prose is not enough because the agent needs an actual checkout to inspect.

Read the full file on GitHub · 975 lines

Files

What ships with it

5 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 · 975 lines · 129 tokens per session scan A 6a0fc8b46380

Subscribe to this mod's changes

agentv-eval-writer is a skill published in the GitHub repository EntityProcess/agentv (15 stars, last pushed 1mo ago), licensed MIT. It adds 129 tokens to every session and 8,818 once invoked, about $0.0006 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 2026-08-30.

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