eval

eval is a skill for Claude Code from vasuag09/harness-claude. It costs 54 tokens per session (764 once invoked), scanned A, original, MIT.

An acceptance-checkpoint tool that compares an implementation with the requirements written in its specification.

In plain words
What is it for?
Use it late in verification to locate the relevant specification, run its automated checks, review manual criteria, and block release while any criterion fails.
Why use it?
Passing tests only shows that code runs; this check also verifies that the promised behavior and other acceptance criteria have been met.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is node scripts/eval/checkpoint.js [spec.md].

Part of the harness-claude plugin — 32 skills, 8 agents, 6 hooks, 3 MCP servers shipped together

Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/vasuag09/harness-claude
agentmods
npx agentmods add skills/vasuag09/harness-claude/eval

Made for: Claude Code.

Or install harness-claude, the plugin that ships this one along with the rest of its 32 skills, 8 agents, 6 hooks, 3 MCP servers.

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 eval

README.md
[![agentmods](https://agentmods.dev/badge/skills/vasuag09/harness-claude/eval.svg)](https://agentmods.dev/skills/vasuag09/harness-claude/eval)
Your own site
<a href="https://agentmods.dev/skills/vasuag09/harness-claude/eval"><img src="https://agentmods.dev/badge/skills/vasuag09/harness-claude/eval.svg" alt="Measured on agentmods" height="20"></a>
Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 764 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00054 $0.00764
Opus 5 $0.00027 $0.00382
Sonnet 5 $0.00011 $0.00153
Haiku 4.5 $0.00005 $0.00076

Measured 6d ago against content hash 555e99800631, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

eval scanned grade A with 1 finding 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 6d 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.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

- **` ```eval ` fences are shell-executed** (via `_lib.sh` → `execSync`) with your privileges.
skills/eval/SKILL.md · 54 lines

How it starts

The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/eval — acceptance-criteria checkpoint

Goal: prove the work satisfies the spec it was built against, criterion by criterion. Green tests show the code runs; this shows it meets what was promised.

Opt-in. This skill is not invoked by any default-pipeline skill or hook. Running it is always explicit; it changes no baseline behavior. (Fulfills v0.4 AC-6 / v0.3 AC-E5.)

Do this

  1. Locate the spec. Default to the latest docs/specs/*.md; let the user name one if the change targets an older spec. Confirm it's the spec this change was built against.
  2. Run the deterministic gate:
    node scripts/eval/checkpoint.js [spec.md]
    
    It prints a per-criterion table (PASS / FAIL / MANUAL) and exits 0 (all PASS, none manual) · 1 (a check FAILED) · 2 (no failures, but MANUAL criteria remain).
    • Each criterion may carry an inline ```eval fenced shell command — that's its machine-check. Add one to an AC when a deterministic check exists (port it from the spec's own test commands).
  3. On FAIL (exit 1): the criterion is objectively unmet. Fix the implementation (not the criterion) and re-run. Do not proceed while any check FAILs.
  4. Adjudicate MANUAL (exit 2): for each prose criterion the script can't decide, gather concrete evidence (run the app, read the diff, check .claude/traces/ for what fired) and judge PASS or FAIL yourself. The script never auto-passes prose — closing these is your job. If a MANUAL criterion is genuinely verifiable, prefer adding an ```eval fence so it's deterministic next time.
  5. Gate. Ship only when every criterion is PASS — checks green and every MANUAL adjudicated PASS with evidence. Report the verdict criterion by criterion.

Security & trust

  • ```eval fences are shell-executed (via _lib.shexecSync) with your privileges. They are author-authored, committed markdown — trust them exactly like the repo's own test scripts or build hooks. Review specs from untrusted branches/PRs before running /eval.
  • checkpoint.js --list is the safe inspect-before-run path: it parses and shows which ACs carry a check, but executes nothing.
  • Secret-safe: a check's output is never printed. On FAIL the report shows only the exit code + the command (committed text), so you re-run it yourself to inspect output.
  • Each check is bounded by a 60s timeout.

Read the full file on GitHub · 54 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. 6d ago First seen · 54 lines · 54 tokens per session scan A 555e99800631

Subscribe to this mod's changes

eval is a skill published in the GitHub repository vasuag09/harness-claude (2 stars, last pushed 1mo ago), licensed MIT. It adds 54 tokens to every session and 764 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Related

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