Software · Web app · 2026

agents-skill-eval

A production evaluator that scores agent skill packages on quality, cost and reliability.

Role
Design, frontend, evaluation engine
Stack
Deterministic checks, optional AI review
Link
agents-skill-eval.com ↗
agents-skill-eval run showing all evaluation phases complete and an overall result of 96 out of 100, rated Excellent
Overview

One evaluator, two entry points

agents-skill-eval takes a SKILL.md package — either as a local folder or a GitHub URL — and runs it through the same production evaluator, returning a single structured report. It exists because "does this skill actually work well?" was being answered by gut feel instead of measurement.

The challenge

Making quality legible and cheap to check

Skill packages fail in quiet ways: drift from the spec, weak trigger phrasing, bloated token footprints, ambiguous instructions, and security footguns. The goal was a deterministic core that anyone can run repeatably, with an optional AI pass for the judgement calls a rule set cannot make.

The approach

Deterministic first, AI optional

Every run goes through deterministic checks and produces a downloadable JSON report. An optional AI review can be layered on top with a provider of choice, kept strictly opt-in so a default run stays fast, private and reproducible.

Architecture
From skill package to structured report
  1. 01
    Input
    Local folder or GitHub blob / tree URL
  2. 02
    Deterministic checks
    Spec · security · tokens · effectiveness
  3. 03
    Optional AI review
    Groq · Gemini · Anthropic · OpenAI
  4. 04
    Report
    Scored result + downloadable JSON

Both entry points run through the identical production evaluator, so a local run and a hosted run return the same report format.

What it does
  • Spec compliance checks

    Every skill gets checked against the spec it is supposed to follow, and anything non-standard is flagged immediately. That catches the kind of drift that works fine on one machine and quietly breaks on the next.

  • Security review

    Overly broad permissions, unguarded deletes and hardcoded paths are flagged before a skill goes anywhere near real data. Nothing is sent to a third-party AI provider unless that is explicitly switched on for the run.

  • Token-efficiency analysis

    Every skill costs a little context each time it loads, so bloat adds up fast across a team. The evaluator flags padding and duplication and names exactly which section to trim.

  • Effectiveness scoring

    The biggest check is the simplest question: will this actually work? Ambiguous instructions, weak examples and vague trigger wording all get caught here — vague wording is the single most common reason a skill never fires.

  • Local folder or GitHub URL input

    Point it at a folder on disk or paste a GitHub link — either way it runs through the same evaluator and gets the same report, so results are always comparable.

  • Deterministic by default

    A default run uses no AI model at all, so it is free to run and returns the same result every time. That makes it safe to run on every commit instead of saving it for a release, and nothing leaves the machine unless asked to.

  • Optional AI review (opt-in)

    Some judgement calls need more than a rule set. An optional AI pass, in a provider of choice, layers on top of the deterministic result — but only when it is switched on, so a default run stays fast, private and repeatable.

  • Downloadable JSON report

    Every run returns a score out of 100, a plain-language rating, and a full breakdown of what failed and why. The report is machine-readable, so it drops straight into CI without extra glue code.

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