Agent skill

Skill Forge Eval

by AgriciDaniel in AgriciDaniel/skill-forge

Run evaluation pipelines on Claude Code skills to test triggering accuracy, workflow correctness, and output quality.

MITAuto-check passedAgent Workflows

Install Skill Forge Eval

skills CLI
$ npx skills add AgriciDaniel/skill-forge --skill skill-forge-eval -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install AgriciDaniel/skill-forge skill-forge-eval --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/AgriciDaniel/skill-forge.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/skill-forge-eval .claude/skills/skill-forge-eval && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
skill-forge-eval
GitHub stars
177
Token cost
~1.7k tokens
SKILL.md length
494 words
Files
1
Skills in repo
9
Repo updated
First seen
Licence
MIT

At a glance

Run evaluation pipelines on Claude Code skills to test triggering accuracy, workflow correctness, and output quality.

  • Works in 7 steps: Define Eval Set → Set Up Workspace → Execute Eval Runs → …
  • User says eval skill
  • SKILL.md covers Process, Advanced: Blind Comparison, Error Handling and Quality Gates
  • Calls python

What it does

Skill Forge Eval is an agent skill from AgriciDaniel/skill-forge. Run evaluation pipelines on Claude Code skills to test triggering accuracy, workflow correctness, and output quality. Spawns executor, grader, comparator, and analyzer sub-agents for parallel evaluation. Generates evalmetadata.json, grading.json, and feedback reports. Use when user says "eval skill", "test skill", "run evals", "evaluate skill", "skill evals", "test skill quality", "run skill tests", or "skill evaluation".

Its SKILL.md is about 1.7k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Agent Workflows, covering Agent evaluation and testing, LLM evaluation and Subagents. The repository describes itself as: Ultimate Claude Code skill creator — design, scaffold, build, review, evolve, and publish production-grade AI agent skills. The licence is MIT.

When your agent uses it

  • User says eval skill
  • Test skill quality
  • Run skill tests
  • Skill evaluation

Example prompts

  • “eval skill”
  • “test skill”
  • “run evals”
  • “/skill-forge-eval”

Requirements

  • Python 3

Workflow steps

7 steps, taken from the step headings in SKILL.md.

  1. Define Eval Set
  2. Set Up Workspace
  3. Execute Eval Runs
  4. Grade Results
  5. Aggregate and Analyze
  6. Present Results
  7. Collect Feedback

What it can do on your machine

Read from SKILL.md and the folder at commit 2872ee9. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Shell commands in SKILL.md call:

    • python

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    No URLs in SKILL.md.

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Skill Forge Eval loads about 1.7k tokens when it runs. Until then it costs about 111 tokens; SKILL.md has 494 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~111
When it runs · the whole SKILL.md, loaded when a task matches
~1.7k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from AgriciDaniel/skill-forge at commit 2872ee9, republished under its MIT licence (© AgriciDaniel). 494 words, ~1,703 tokens.

Download SKILL.mdSave it as .claude/skills/skill-forge-eval/SKILL.md (or your agent's skills folder).
name
skill-forge-eval
description
Run evaluation pipelines on Claude Code skills to test triggering accuracy, workflow correctness, and output quality. Spawns executor, grader, comparator, and analyzer sub-agents for parallel evaluation. Generates eval_metadata.json, grading.json, and feedback reports. Use when user says "eval skill", "test skill", "run evals", "evaluate skill", "skill evals", "test skill quality", "run skill tests", or "skill evaluation".

Skill Evaluation Pipeline

Run structured evaluations against Claude Code skills to verify triggering, correctness, and quality using a multi-agent pipeline.

Process

Step 1: Define Eval Set

Accept eval definitions from:

  • Path to eval set JSON: evals/evals.json or user-specified file
  • Inline prompts: User provides eval queries directly
  • Auto-generated: Generate from skill description (see Step 1b)

Eval set JSON schema:

json
{
  "skill_name": "my-skill",
  "skill_path": "./my-skill",
  "evals": [
    {
      "eval_id": 0,
      "eval_name": "descriptive-name",
      "prompt": "The user's task prompt",
      "input_files": [],
      "assertions": [
        {
          "name": "output-has-score",
          "check": "Output contains a numeric score between 0-100",
          "weight": 1.0
        }
      ],
      "should_trigger": true
    }
  ]
}
Step 1b: Auto-Generate Eval Set

If no eval set exists, generate one:

  1. Read the skill's SKILL.md description and instructions
  2. Run python scripts/generate_eval_set.py <skill-path> to produce a starter set
  3. Present the generated set to the user for review and editing
  4. User approves or modifies before proceeding
Step 2: Set Up Workspace

Create the eval workspace outside the skill directory to avoid confusing eval artifacts with skill files. Use a sibling directory or a dedicated location:

eval-workspace/
  iteration-1/
    eval-0/
      eval_metadata.json        # Assertions and config for this eval
      with_skill/
        outputs/                # Skill execution outputs
        timing.json             # Token count + duration
        grading.json            # Assertion results + evidence
      baseline/
        outputs/
        timing.json
        grading.json
    eval-1/
      eval_metadata.json
      with_skill/
        outputs/
        timing.json
        grading.json
      baseline/
        outputs/
        timing.json
        grading.json
    benchmark.json              # Aggregated metrics
    benchmark.md                # Human-readable report

For each eval directory, create eval_metadata.json from the eval set entry:

json
{
  "eval_id": 0,
  "eval_name": "descriptive-name",
  "prompt": "The user's task prompt",
  "assertions": [...],
  "should_trigger": true
}
Step 3: Execute Eval Runs

For each eval in the set, spawn two parallel runs:

With-skill run (delegate to agents/skill-forge-executor.md):

Execute this task:
- Skill path: <path-to-skill>
- Task: <eval prompt>
- Input files: <eval files if any, or "none">
- Save outputs to: <workspace>/iteration-<N>/eval-<ID>/with_skill/outputs/
- Outputs to save: <what the assertions check>

Baseline run (delegate to agents/skill-forge-executor.md):

  • For new skills: run without the skill loaded
  • For improved skills: run with the previous version (snapshot it first)

Save timing data to timing.json in each run directory:

json
{
  "total_tokens": 84852,
  "duration_ms": 23332,
  "total_duration_seconds": 23.3
}
Step 4: Grade Results

Delegate to agents/skill-forge-grader.md for each completed run:

  1. Grade against assertions defined in eval_metadata.json
  2. Save results to grading.json per run:
json
{
  "eval_id": 0,
  "run_type": "with_skill",
  "assertions": [
    {
      "name": "output-has-score",
      "passed": true,
      "evidence": "Found score: 87/100 on line 14"
    }
  ],
  "pass_rate": 1.0
}
Step 5: Aggregate and Analyze
  1. Run python scripts/aggregate_benchmark.py <workspace>/iteration-<N> --skill-name <name>

  2. This produces benchmark.json and benchmark.md with:

    • Pass rate per eval (with_skill vs baseline)
    • Average time and token usage
    • Improvement ratio (with_skill / baseline)
  3. Delegate to agents/skill-forge-analyzer.md to:

    • Surface patterns that aggregate stats might hide
    • Identify consistently failing assertion types
    • Flag regressions from previous iterations
Step 6: Present Results

Generate a summary report:

markdown
# Eval Report: [skill-name] — Iteration [N]

## Overall
| Metric | With Skill | Baseline | Delta |
|--------|-----------|----------|-------|
| Pass Rate | X% | Y% | +Z% |
| Avg Time | Xs | Ys | -Zs |
| Avg Tokens | X | Y | -Z |

## Per-Eval Results
| Eval | With Skill | Baseline | Status |
|------|-----------|----------|--------|
| eval-0 | PASS | FAIL | Improved |
| eval-1 | PASS | PASS | Maintained |

## Patterns & Insights
[From analyzer agent]

## Recommendations
[Specific improvements based on failures]
Show full SKILL.md (204 more words)Show less
Step 7: Collect Feedback

Save user feedback to feedback.json:

json
{
  "reviews": [
    {
      "run_id": "eval-0-with_skill",
      "feedback": "the chart is missing axis labels",
      "timestamp": "2026-03-06T12:00:00Z"
    }
  ],
  "status": "complete"
}

Pass feedback to /skill-forge evolve for the next iteration.

Advanced: Blind Comparison

For rigorous A/B testing between skill versions:

  1. Delegate to agents/skill-forge-comparator.md
  2. Pass two directories: eval-<ID>/with_skill/outputs/ and eval-<ID>/baseline/outputs/
  3. Comparator assigns random labels (Version A / Version B) so it cannot know which is new
  4. Rates each output on assertion criteria from eval_metadata.json
  5. Returns preference scores without knowing which is "new" vs "old"

Error Handling

  • Executor timeout: If a run exceeds 5 minutes, terminate and mark as "timed_out": true in timing.json
  • Executor failure: If a run crashes, save the error to error.txt in the run directory and continue with remaining evals
  • Grading failure: If grading cannot determine pass/fail, mark assertion as "passed": null with evidence explaining why
  • Missing files: If timing.json or grading.json is missing after a run, flag the eval as incomplete in the report
  • Partial completion: Always aggregate and report whatever results are available — do not block on one failed eval

Quality Gates

Before marking an eval run as complete:

  • All evals executed (with_skill + baseline)
  • Timing data captured for every run
  • All assertions graded with evidence
  • Benchmark aggregated with pass rate, time, tokens
  • Analyzer patterns documented
  • Results presented to user

© AgriciDaniel, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in skills/skill-forge-eval of AgriciDaniel/skill-forge.

Open the folder on GitHubat commit 2872ee9

Compare with similar skills

Skill Forge Eval next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Skill Forge Eval compared with similar skills
SkillStarsUsed inTokensAuto-checkLicenceRepo updated
Skill Forge Eval this skillAgriciDaniel/skill-forge177—~1.7kAutomated safety check: PassMIT
Kayba Pipelinekayba-ai/agentic-context-engine2.6k—~1.4kAutomated safety check: PassApache-2.0
Harness Evaltech-leads-club/agent-skills7k—~3.9kAutomated safety check: PassCC-BY-4.0
Waza Skill Evaluatormicrosoft/waza1.4k—~2kAutomated safety check: PassMIT
Eval Answermalloydata/publisher116—~4.3kAutomated safety check: PassMIT
Waza Interactivemicrosoft/waza1.4k—~1.3kAutomated safety check: PassMIT

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Categories

Questions about Skill Forge Eval

What does Skill Forge Eval do?

Run evaluation pipelines on Claude Code skills to test triggering accuracy, workflow correctness, and output quality. Skill Forge Eval is an agent skill from AgriciDaniel/skill-forge. Run evaluation pipelines on Claude Code skills to test triggering accuracy, workflow correctness, and output quality.

When should I use Skill Forge Eval?

Skill Forge Eval fits situations like: user says eval skill; test skill quality; run skill tests; skill evaluation.

How do I install Skill Forge Eval in Claude Code?

Run `npx skills add AgriciDaniel/skill-forge --skill skill-forge-eval -a claude-code`. Or copy the skill folder (skills/skill-forge-eval in AgriciDaniel/skill-forge) into .claude/skills/skill-forge-eval in your project. Claude Code loads it when a task matches its description.

How do I install Skill Forge Eval in Codex?

Run `npx skills add AgriciDaniel/skill-forge --skill skill-forge-eval -a codex`. Or copy the skill folder (skills/skill-forge-eval in AgriciDaniel/skill-forge) into .agents/skills/skill-forge-eval in your project. Codex loads it when a task matches its description.

Can I use Skill Forge Eval in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add AgriciDaniel/skill-forge --skill skill-forge-eval -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/skill-forge-eval, .gemini/skills/skill-forge-eval, .github/skills/skill-forge-eval and .opencode/skills/skill-forge-eval in your project.

What does Skill Forge Eval need to run?

Going by SKILL.md and its folder, Skill Forge Eval needs the command-line tools its instructions call (python). Our summary lists: Python 3.

Does Skill Forge Eval access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Skill Forge Eval safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Skill Forge Eval use?

Skill Forge Eval is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Skill Forge Eval use?

About 1.7k tokens (SKILL.md is roughly 6.8k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Skill Forge Eval?

Skills that share tags, products or a category with Skill Forge Eval: Kayba Pipeline (kayba-ai/agentic-context-engine, 2.6k stars), Harness Eval (tech-leads-club/agent-skills, 7k stars), Waza Skill Evaluator (microsoft/waza, 1.4k stars) and Eval Answer (malloydata/publisher, 116 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Skill Forge Eval?

AgriciDaniel (a GitHub user) maintains it in AgriciDaniel/skill-forge, which has 177 GitHub stars. The repository holds 9 skills in this directory. The repository was last updated on April 10, 2026.

Source: AgriciDaniel/skill-forge on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.