Agent Eval

Agent Eval Skill

Evaluate any agent session — coding, creative, research, video production, anything. The skill reads the trace, discovers what test cases make sense for that workflow, stores them in the project's .agent-eval/ directory, and grades the session.

When to Use This Skill

• Analyze a completed agent session export (trace file, JSONL, or markdown)
• Grade a live agent session after it finishes
• Build project-specific eval criteria that evolve with the workflow
• Check whether the agent invoked the correct skill when prompted
• Track scaffold improvement over time via logged scores
• Generate eval candidates and harness fix recommendations

Quick Start

# Grade a session — auto-discover and save criteria in the project
/skill:agent-eval /path/to/session-export.md

# Grade with explicit project directory (where .agent-eval/ will be created)
/skill:agent-eval --project @repos/videos /path/to/session-export.md

# Grade and tag the harness version
/skill:agent-eval --tag "prompt-v2.1" /path/to/session-export.md

# Grade a live session (read from stdin)
cat session.md | /skill:agent-eval --stdin --project ~/my-project

Arguments

How It Works

Phase 1: Ingest the Trace

Read the session trace. Supported formats:

• Markdown (.md) — pi session exports, conversation logs
• JSONL (.jsonl) — structured event streams
• Plain text — any readable transcript

Extract:

• Task description (first user message)
• Agent responses
• Tool calls and their arguments
• File changes
• Commands executed
• Skill invocations (detected via /skill:name or $skill-name patterns)
• Domain signals — what kind of workflow is this? (coding, video, research, etc.)

Phase 2: Discover or Load Eval Criteria

This is the key innovation. The skill doesn't assume coding workflows.

If .agent-eval/criteria.json exists in the project:

Load it. Use those criteria.

If no criteria exist (first run):

The skill analyzes the trace and auto-generates appropriate test cases:

Analyzing trace...
Detected domain: video-production
Detected tools: file-read, file-write, bash(youtube-dl), bash(ffmpeg)
Detected skills: /skill:video-edit

Generating project-specific criteria...

The generated criteria are saved to {project}/.agent-eval/criteria.json.

Example: Video Production Criteria

{
  "version": "2026-06-04",
  "project": "@repos/videos",
  "domain": "video-production",
  "generated_from": "session-2026-06-04.md",
  "criteria": [
    {
      "id": "skill-invocation",
      "name": "Skill Invocation",
      "check_type": "pattern",
      "pattern": "/skill:video-edit|\\$video-edit",
      "required": true
    },
    {
      "id": "downloaded-source",
      "name": "Downloaded Source Material",
      "check_type": "command_pattern",
      "patterns": ["youtube-dl", "yt-dlp", "wget", "curl -O"],
      "required": false
    },
    {
      "id": "checked-video-format",
      "name": "Checked Video Format",
      "check_type": "command_pattern",
      "patterns": ["ffprobe", "mediainfo", "file ", "ffmpeg -i"],
      "required": false
    },
    {
      "id": "created-output-file",
      "name": "Created Output File",
      "check_type": "file_exists",
      "required": false
    },
    {
      "id": "verified-output-quality",
      "name": "Verified Output Quality",
      "check_type": "llm_judge",
      "rubric": {
        "levels": [
          {
            "score": 1.0,
            "label": "Fully Verified",
            "criteria": "Agent checks output file exists, verifies format/codec, confirms duration, and previews result",
            "evidence_required": "Quote verification steps"
          },
          {
            "score": 0.50,
            "label": "Partially Verified",
            "criteria": "Agent checks output exists but doesn't verify quality or format",
            "evidence_required": "Quote what was checked and what was skipped"
          },
          {
            "score": 0.0,
            "label": "Not Verified",
            "criteria": "Agent declares success without checking output",
            "evidence_required": "Quote declaration without verification"
          }
        ]
      },
      "contributes_to_dimension": "verification",
      "dimension_weight": 0.60
    }
  ]
}

Example: Research / Writing Criteria

{
  "domain": "research-writing",
  "criteria": [
    {
      "id": "skill-invocation",
      "check_type": "pattern",
      "pattern": "/skill:research|\\$research",
      "required": true
    },
    {
      "id": "gathered-sources",
      "name": "Gathered Sources",
      "check_type": "llm_judge",
      "rubric": {
        "levels": [
          {
            "score": 1.0,
            "label": "Thorough Research",
            "criteria": "Agent identifies and reads 3+ relevant sources, cites them explicitly",
            "evidence_required": "Quote source references and how they were used"
          },
          {
            "score": 0.50,
            "label": "Minimal Research",
            "criteria": "Agent mentions sources but doesn't deeply engage with them",
            "evidence_required": "Quote source mentions"
          },
          {
            "score": 0.0,
            "label": "No Research",
            "criteria": "Agent writes from prior knowledge without gathering new sources",
            "evidence_required": "Note absence of source gathering"
          }
        ]
      }
    },
    {
      "id": "structured-output",
      "name": "Structured Output",
      "check_type": "llm_judge",
      "rubric": {
        "levels": [
          {
            "score": 1.0,
            "label": "Well Structured",
            "criteria": "Output has clear sections, headings, logical flow, and summary",
            "evidence_required": "Describe structure"
          },
          {
            "score": 0.0,
            "label": "Unstructured",
            "criteria": "Output is a wall of text without organization",
            "evidence_required": "Note absence of structure"
          }
        ]
      }
    }
  ]
}

Phase 3: Run Deterministic Checks

Fast, rule-based checks from the project's criteria:

Phase 4: LLM-as-Judge Grading (Rubric-Based)

For semantic criteria, use structured rubric levels with evidence requirements.

Why rubric-based? Raw LLM scores hallucinate. Rubric-based scoring forces:

1. Match evidence to explicit level definitions
2. Quote specific evidence from the trace
3. Explain reasoning
4. Self-report confidence

Judge Output Format

{
  "criterion_id": "verified-output-quality",
  "score": 0.50,
  "level_matched": "Partially Verified",
  "confidence": "high",
  "evidence": [
    {
      "turn": 15,
      "quote": "Agent: 'The video has been rendered to output.mp4'",
      "relevance": "Confirmed output file was created"
    }
  ],
  "reasoning": "Agent confirmed output file exists but did not verify codec, duration, or quality. No ffprobe or playback check. Matches 'Partially Verified' level.",
  "missing_evidence": [
    "Would need ffprobe output or quality check for 'Fully Verified'"
  ]
}

Self-Consistency Check

Run judge 3 times, flag if variance ≥ 0.15.

Dimension Scoring

Phase 5: Evolve the Criteria

After each eval, the skill can suggest criteria additions:

New failure mode detected: Agent didn't check video codec before re-encoding

Suggested criterion to add to .agent-eval/criteria.json:
{
  "id": "checked-codec",
  "name": "Checked Source Codec",
  "check_type": "command_pattern",
  "patterns": ["ffprobe", "ffmpeg -i"],
  "rationale": "Re-encoding without checking codec can cause quality loss"
}

Add this criterion? (y/n)

The criteria evolve with the workflow:

• Coding project → tests, linting, type checking
• Video project → format checks, quality verification, source attribution
• Research project → source gathering, citation, fact-checking
• Design project → asset organization, naming conventions, export verification

Phase 6: Log to JSONL

Append to ~/.pi/agent/evals/results.jsonl:

{
  "eval_id": "eval-20260604-153022-a1b2c3d",
  "timestamp": "2026-06-04T15:30:22Z",
  "project": "@repos/videos",
  "trace_path": "/path/to/session-export.md",
  "task": "Create a highlight reel from source footage",
  "tag": "prompt-v2.1",
  "domain": "video-production",
  "expected_skill": "video-edit",
  "skill_invoked": true,
  "scores": {
    "correctness": 0.80,
    "efficiency": 0.65,
    "tool_use": 0.85,
    "verification": 0.40,
    "overall": 0.70
  },
  "deterministic_checks": {
    "skill_invocation": { "pass": true },
    "downloaded-source": { "pass": true },
    "created-output-file": { "pass": true }
  },
  "llm_judgments": {
    "verified-output-quality": { "score": 0.50, "confidence": "high" }
  },
  "criteria_version": "2026-06-04-v1",
  "criteria_path": "@repos/videos/.agent-eval/criteria.json"
}

Phase 7: Generate Report

Write report to {output-dir}/{eval-id}/report.md:

# Agent Eval Report

## Session Metadata
- **Eval ID:** eval-20260604-153022-a1b2c3d
- **Project:** @repos/videos
- **Domain:** video-production
- **Task:** Create a highlight reel from source footage
- **Tag:** prompt-v2.1
- **Expected Skill:** video-edit
- **Skill Invoked:** ✅ Yes

## Scores

| Dimension | Score | Weight | Weighted |
|-----------|-------|--------|----------|
| Correctness | 0.80 | 40% | 0.32 |
| Efficiency | 0.65 | 25% | 0.16 |
| Tool Use | 0.85 | 20% | 0.17 |
| Verification | 0.40 | 15% | 0.06 |
| **Overall** | | | **0.70** |

## Deterministic Checks

| Check | Result | Evidence |
|-------|--------|----------|
| Skill invocation | ✅ PASS | Found `/skill:video-edit` at turn 2 |
| Downloaded source | ✅ PASS | `yt-dlp` command at turn 4 |
| Checked video format | ❌ FAIL | No `ffprobe` or `ffmpeg -i` found |
| Created output file | ✅ PASS | `output.mp4` exists |

## LLM Judge Results

📝 Verified Output Quality — 0.50 (Partially Verified)
   Evidence: Confirmed output exists but no codec/duration check
   Confidence: high

## Criteria

Loaded from: `@repos/videos/.agent-eval/criteria.json`
Version: 2026-06-04-v1

## Suggested Criteria Additions

Based on this session, consider adding:
- `checked-codec` — verify source codec before re-encoding
- `verified-duration` — confirm output duration matches expectation

## Recommendations

### Medium
1. **Add video format verification** — agent didn't check source codec
   before re-encoding, risking quality loss

## Eval Candidates
- `agent_checks_video_codec_before_encode`

The Project-Local Criteria System

Directory Structure

Each project that uses agent-eval gets an .agent-eval/ directory:

@repos/videos/
├── .agent-eval/
│   ├── criteria.json          # Living criteria for this project
│   ├── criteria-history/      # Previous versions
│   │   ├── criteria-2026-06-01.json
│   │   └── criteria-2026-06-04.json
│   └── reports/               # Per-session reports
│       ├── eval-20260601-120000.md
│       └── eval-20260604-153022.md
├── src/
├── footage/
└── output/

Criteria Evolution

# First run — auto-generate criteria
/skill:agent-eval --project @repos/videos session-01.md
# Creates @repos/videos/.agent-eval/criteria.json

# Second run — criteria exist, use and refine
/skill:agent-eval --project @repos/videos session-02.md
# Uses existing criteria, suggests additions based on new failure modes

# Third run — criteria have evolved
/skill:agent-eval --project @repos/videos session-03.md
# More comprehensive, project-specific checks

Sharing Criteria Across Similar Projects

# Copy criteria from one video project to another
cp @repos/videos/.agent-eval/criteria.json @repos/podcasts/.agent-eval/criteria.json

# Then adapt
cd @repos/podcasts
# Edit criteria.json to replace video-specific with audio-specific checks

Domain Detection

The skill auto-detects the workflow domain from trace signals:

You can override:

/skill:agent-eval --domain video-production session.md

Multi-Domain Projects

Some projects span domains. The criteria can mix checks:

{
  "domain": "mixed",
  "criteria": [
    { "id": "backend-tests", "check_type": "command_pattern", "patterns": ["pytest"] },
    { "id": "frontend-build", "check_type": "command_pattern", "patterns": ["npm run build"] },
    { "id": "api-documentation", "check_type": "llm_judge", "rubric": { ... } }
  ]
}

Integration with agent-benchmark

Both skills share:

• Scoring rubric (4 dimensions, same weights)
• JSONL log format
• Eval candidate generation

Use agent-eval for:

• Single-session analysis
• Building project-specific criteria
• Quick checks after harness changes

Use agent-benchmark for:

• Multi-model comparison
• Regression testing
• Scheduled/CI evaluation

Files Reference

Troubleshooting

Key Principles

1. Evals are project-local — Criteria live with the project they evaluate
2. Criteria evolve — Each session can improve the criteria
3. Domain-agnostic — Works for coding, video, research, anything
4. Evidence-based — Every score needs quoted evidence
5. Human-in-the-loop — Suggest additions, you approve