evaluate-skill

evaluate-skill is a skill for Claude Code, Codex from edonadei/caliper. It costs 60 tokens per session (888 once invoked), scanned A, original, MIT.

A testing guide for measuring how reliably a skill works. It uses repeated runs and pass@k, a measure of whether at least one of several attempts succeeds, and can compare results with the base agent.

In plain words
What is it for?
Use it to run or design skill evaluations, interpret reliability results, or create an `.eval.yaml` file describing evaluation tasks.
Why use it?
It replaces informal testing with repeatable checks and explicit success criteria. It also identifies whether a skill behaves consistently across runs.

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/edonadei/caliper/evaluate-skill
Any agent
npx skills add edonadei/caliper --skill evaluate-skill
Clone the repo
git clone --depth 1 https://github.com/edonadei/caliper

Made for: Claude Code, Codex.

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 evaluate-skill

README.md
[![agentmods](https://agentmods.dev/badge/skills/edonadei/caliper/evaluate-skill.svg)](https://agentmods.dev/skills/edonadei/caliper/evaluate-skill)
Your own site
<a href="https://agentmods.dev/skills/edonadei/caliper/evaluate-skill"><img src="https://agentmods.dev/badge/skills/edonadei/caliper/evaluate-skill.svg" alt="Measured on agentmods" height="20"></a>
Per session 60 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 888 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 $0.00060 $0.00888
Opus 5 $0.00030 $0.00444
Sonnet 5 $0.00012 $0.00178
Haiku 4.5 $0.00006 $0.00089

Measured 4d ago against content hash 14911ba6094f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

evaluate-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 4d 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.

skills/evaluate-skill/SKILL.md · 59 lines

How it starts

The opening of the file, as written. The whole thing — 59 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Evaluate Skill

Run a skill repeatedly to measure how reliably it works, and design the evals that measure it.

Prerequisites

The caliper CLI must be on PATH. This skill can be copied into an agent without the Caliper repo, so do not assume the CLI is packaged with it. Install if missing:

pipx install caliper-eval

The engine (backend + model) is not part of the spec — it is chosen at run time with --model (skill) and --judge-model (judge), independently, from claude-code, codex, pi, defaulting to claude-code. Every backend is a CLI agent that uses its own subscription/auth; there is no direct-API backend (for API billing, configure a CLI with an API key). Full per-backend detail and every command: REFERENCE.md.

Spec shape

An .eval.yaml names the skill and a list of tasks. Keep skill.path relative to the spec file (usually ./SKILL.md):

skill:
  path: ./SKILL.md      # relative to the spec file
tasks:
  - name: What success looks like
    prompt: <prompt sent to the skill under test>
    expect: <natural-language pass/fail criterion>
    assert: |           # optional deterministic Python check
      assert ...

The spec has no backend/model or judge: block; pick the engine when you run, e.g. caliper run <spec> --model codex --judge-model codex. The full format (setup/cleanup, external assert scripts, sandbox) is in REFERENCE.md.

Bundled references

references/evals/ holds complete real examples (Claude Code smoke, commit workflow, screenshot, summarization, TDD) — each folder self-contained with its fixture SKILL.md and .eval.yaml. references/simple.eval.yaml is one compact multi-task spec.

No eval yet?

If the skill has a SKILL.md but no .eval.yaml, suggest the grill-skill workflow — it interviews the user and generates a happy/edge/adversarial spec. Use evaluate-skill directly when a spec already exists and the user wants to run, validate, report, or extend it.

Read the full file on GitHub · 59 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. 4d ago First seen · 59 lines · 60 tokens per session scan A 14911ba6094f

Subscribe to this mod's changes

evaluate-skill is a skill published in the GitHub repository edonadei/caliper (50 stars, last pushed 4d ago), licensed MIT. It adds 60 tokens to every session and 888 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 2026-08-30.

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