skill-evaluation

skill-evaluation is a skill for Claude Code, Codex from AnthonyPoschen/agent-skills. It costs 44 tokens per session (920 once invoked), scanned A, original, MIT.

An evaluation method for checking whether an agent skill changes how an agent behaves and the quality of its work.

In plain words
What is it for?
It helps test whether a skill triggers when it should, compare old and new versions, and investigate poor results.
Why use it?
It replaces guesswork and self-reported compliance with tests using realistic prompts, a shared scoring guide, and blinded review.

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/anthonyposchen/agent-skills/skill-evaluation
Any agent
npx skills add AnthonyPoschen/agent-skills --skill skill-evaluation
Clone the repo
git clone --depth 1 https://github.com/AnthonyPoschen/agent-skills

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 skill-evaluation

README.md
[![agentmods](https://agentmods.dev/badge/skills/anthonyposchen/agent-skills/skill-evaluation.svg)](https://agentmods.dev/skills/anthonyposchen/agent-skills/skill-evaluation)
Your own site
<a href="https://agentmods.dev/skills/anthonyposchen/agent-skills/skill-evaluation"><img src="https://agentmods.dev/badge/skills/anthonyposchen/agent-skills/skill-evaluation.svg" alt="Measured on agentmods" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 920 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 5.1 $0.00044 $0.00920
Opus 5 $0.00022 $0.00460
Sonnet 5 $0.00009 $0.00184
Haiku 4.5 $0.00004 $0.00092

Measured 5d ago against content hash 8f2efd6c9c61, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

skill-evaluation 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 5d 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/skill-evaluation/SKILL.md · 119 lines

How it starts

The opening of the file, as written. The whole thing — 119 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill Evaluation

Use this skill to decide whether a skill helps on real work. Do not judge a skill by how convincing its instructions sound or by an agent saying it followed them.

Use this skill for a new public skill, a meaningful change to an existing skill, or a skill that seems to trigger at the wrong time or produce poor work. Skip it for a small wording change unless the change has meaningful uncertainty or risk.

State The Question

Start with one question the evaluation can answer.

Good questions:

  • Does this skill trigger for the writing tasks it claims to handle?
  • Does the new version produce clearer release notes than the old version?
  • Does this refactoring skill reduce unnecessary abstractions on a real task?

Do not combine several unrelated questions in one evaluation.

Evaluate Triggering Separately

Test the skill description with a small set of realistic prompts. Include both prompts that should trigger the skill and prompts that should not.

For each prompt, record:

  • whether the skill should trigger;
  • whether it did trigger;
  • why the result was correct or incorrect.

Use substantive tasks. A trivial prompt may not activate a skill even when its description is correct, because the agent can solve it without specialised guidance.

Evaluate Behaviour On Real Tasks

Compare candidates on the same task. A candidate can be the new skill, the old skill, a no skill baseline, or another proposed version.

  1. Pick a small number of realistic tasks. Prefer prior user requests, real repository files, or representative changes over artificial prompts.
  2. Write one short shared rubric before running candidates. The rubric must describe the outcome that matters, not the wording of the skill.
  3. Give every candidate the same task, inputs, constraints, and expected output location. Use isolated workspaces when candidates write files.
  4. Save the produced artifacts and direct verification evidence.
  5. Hide candidate identities before judging the artifacts. Read the work and its evidence, not an agent's summary of what it intended to do.
  6. Compare quality, correctness, scope, cost, and unnecessary work.

Read the full file on GitHub · 119 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. 5d ago First seen · 119 lines · 44 tokens per session scan A 8f2efd6c9c61

Subscribe to this mod's changes

skill-evaluation is a skill published in the GitHub repository AnthonyPoschen/agent-skills (2 stars, last pushed 3d ago), licensed MIT. It adds 44 tokens to every session and 920 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 2026-08-31.

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