12 KiB
JSON Schemas
This document defines the JSON schemas used by skill-creator.
evals.json
Defines the evals for a skill. Located at evals/evals.json within the skill directory.
{
"skill_name": "example-skill",
"evals": [
{
"id": 1,
"prompt": "User's example prompt",
"expected_output": "Description of expected result",
"files": ["evals/files/sample1.pdf"],
"expectations": [
"The output includes X",
"The skill used script Y"
]
}
]
}
Fields:
skill_name: Name matching the skill's frontmatterevals[].id: Unique integer identifierevals[].prompt: The task to executeevals[].expected_output: Human-readable description of successevals[].files: Optional list of input file paths (relative to skill root)evals[].expectations: List of verifiable statements
history.json
Tracks version progression in Improve mode. Located at workspace root.
{
"started_at": "2026-01-15T10:30:00Z",
"skill_name": "pdf",
"current_best": "v2",
"iterations": [
{
"version": "v0",
"parent": null,
"expectation_pass_rate": 0.65,
"grading_result": "baseline",
"is_current_best": false
},
{
"version": "v1",
"parent": "v0",
"expectation_pass_rate": 0.75,
"grading_result": "won",
"is_current_best": false
},
{
"version": "v2",
"parent": "v1",
"expectation_pass_rate": 0.85,
"grading_result": "won",
"is_current_best": true
}
]
}
Fields:
started_at: ISO timestamp of when improvement startedskill_name: Name of the skill being improvedcurrent_best: Version identifier of the best performeriterations[].version: Version identifier (v0, v1, ...)iterations[].parent: Parent version this was derived fromiterations[].expectation_pass_rate: Pass rate from gradingiterations[].grading_result: "baseline", "won", "lost", or "tie"iterations[].is_current_best: Whether this is the current best version
grading.json
Output from the grader agent. Located at <run-dir>/grading.json.
{
"expectations": [
{
"text": "The output includes the name 'John Smith'",
"passed": true,
"evidence": "Found in transcript Step 3: 'Extracted names: John Smith, Sarah Johnson'"
},
{
"text": "The spreadsheet has a SUM formula in cell B10",
"passed": false,
"evidence": "No spreadsheet was created. The output was a text file."
}
],
"summary": {
"passed": 2,
"failed": 1,
"total": 3,
"pass_rate": 0.67
},
"execution_metrics": {
"tool_calls": {
"Read": 5,
"Write": 2,
"Bash": 8
},
"total_tool_calls": 15,
"total_steps": 6,
"errors_encountered": 0,
"output_chars": 12450,
"transcript_chars": 3200
},
"timing": {
"executor_duration_seconds": 165.0,
"grader_duration_seconds": 26.0,
"total_duration_seconds": 191.0
},
"claims": [
{
"claim": "The form has 12 fillable fields",
"type": "factual",
"verified": true,
"evidence": "Counted 12 fields in field_info.json"
}
],
"user_notes_summary": {
"uncertainties": ["Used 2023 data, may be stale"],
"needs_review": [],
"workarounds": ["Fell back to text overlay for non-fillable fields"]
},
"eval_feedback": {
"suggestions": [
{
"assertion": "The output includes the name 'John Smith'",
"reason": "A hallucinated document that mentions the name would also pass"
}
],
"overall": "Assertions check presence but not correctness."
}
}
Fields:
expectations[]: Graded expectations with evidencesummary: Aggregate pass/fail countsexecution_metrics: Tool usage and output size (from executor's metrics.json)timing: Wall clock timing (from timing.json)claims: Extracted and verified claims from the outputuser_notes_summary: Issues flagged by the executoreval_feedback: (optional) Improvement suggestions for the evals, only present when the grader identifies issues worth raising
metrics.json
Output from the executor agent. Located at <run-dir>/outputs/metrics.json.
{
"tool_calls": {
"Read": 5,
"Write": 2,
"Bash": 8,
"Edit": 1,
"Glob": 2,
"Grep": 0
},
"total_tool_calls": 18,
"total_steps": 6,
"files_created": ["filled_form.pdf", "field_values.json"],
"errors_encountered": 0,
"output_chars": 12450,
"transcript_chars": 3200
}
Fields:
tool_calls: Count per tool typetotal_tool_calls: Sum of all tool callstotal_steps: Number of major execution stepsfiles_created: List of output files createderrors_encountered: Number of errors during executionoutput_chars: Total character count of output filestranscript_chars: Character count of transcript
timing.json
Wall clock timing for a run. Located at <run-dir>/timing.json.
How to capture: When a subagent task completes, the task notification includes total_tokens and duration_ms. Save these immediately — they are not persisted anywhere else and cannot be recovered after the fact.
{
"total_tokens": 84852,
"duration_ms": 23332,
"total_duration_seconds": 23.3,
"executor_start": "2026-01-15T10:30:00Z",
"executor_end": "2026-01-15T10:32:45Z",
"executor_duration_seconds": 165.0,
"grader_start": "2026-01-15T10:32:46Z",
"grader_end": "2026-01-15T10:33:12Z",
"grader_duration_seconds": 26.0
}
benchmark.json
Output from Benchmark mode. Located at benchmarks/<timestamp>/benchmark.json.
{
"metadata": {
"skill_name": "pdf",
"skill_path": "/path/to/pdf",
"executor_model": "claude-sonnet-4-20250514",
"analyzer_model": "most-capable-model",
"timestamp": "2026-01-15T10:30:00Z",
"evals_run": [1, 2, 3],
"runs_per_configuration": 3
},
"runs": [
{
"eval_id": 1,
"eval_name": "Ocean",
"configuration": "with_skill",
"run_number": 1,
"result": {
"pass_rate": 0.85,
"passed": 6,
"failed": 1,
"total": 7,
"time_seconds": 42.5,
"tokens": 3800,
"tool_calls": 18,
"errors": 0
},
"expectations": [
{"text": "...", "passed": true, "evidence": "..."}
],
"notes": [
"Used 2023 data, may be stale",
"Fell back to text overlay for non-fillable fields"
]
}
],
"run_summary": {
"with_skill": {
"pass_rate": {"mean": 0.85, "stddev": 0.05, "min": 0.80, "max": 0.90},
"time_seconds": {"mean": 45.0, "stddev": 12.0, "min": 32.0, "max": 58.0},
"tokens": {"mean": 3800, "stddev": 400, "min": 3200, "max": 4100}
},
"without_skill": {
"pass_rate": {"mean": 0.35, "stddev": 0.08, "min": 0.28, "max": 0.45},
"time_seconds": {"mean": 32.0, "stddev": 8.0, "min": 24.0, "max": 42.0},
"tokens": {"mean": 2100, "stddev": 300, "min": 1800, "max": 2500}
},
"delta": {
"pass_rate": "+0.50",
"time_seconds": "+13.0",
"tokens": "+1700"
}
},
"notes": [
"Assertion 'Output is a PDF file' passes 100% in both configurations - may not differentiate skill value",
"Eval 3 shows high variance (50% ± 40%) - may be flaky or model-dependent",
"Without-skill runs consistently fail on table extraction expectations",
"Skill adds 13s average execution time but improves pass rate by 50%"
]
}
Fields:
metadata: Information about the benchmark runskill_name: Name of the skilltimestamp: When the benchmark was runevals_run: List of eval names or IDsruns_per_configuration: Number of runs per config (e.g. 3)
runs[]: Individual run resultseval_id: Numeric eval identifiereval_name: Human-readable eval name (used as section header in the viewer)configuration: Must be"with_skill"or"without_skill"(the viewer uses this exact string for grouping and color coding)run_number: Integer run number (1, 2, 3...)result: Nested object withpass_rate,passed,total,time_seconds,tokens,errors
run_summary: Statistical aggregates per configurationwith_skill/without_skill: Each containspass_rate,time_seconds,tokensobjects withmeanandstddevfieldsdelta: Difference strings like"+0.50","+13.0","+1700"
notes: Freeform observations from the analyzer
Important: The viewer reads these field names exactly. Using config instead of configuration, or putting pass_rate at the top level of a run instead of nested under result, will cause the viewer to show empty/zero values. Always reference this schema when generating benchmark.json manually.
comparison.json
Output from blind comparator. Located at <grading-dir>/comparison-N.json.
{
"winner": "A",
"reasoning": "Output A provides a complete solution with proper formatting and all required fields. Output B is missing the date field and has formatting inconsistencies.",
"rubric": {
"A": {
"content": {
"correctness": 5,
"completeness": 5,
"accuracy": 4
},
"structure": {
"organization": 4,
"formatting": 5,
"usability": 4
},
"content_score": 4.7,
"structure_score": 4.3,
"overall_score": 9.0
},
"B": {
"content": {
"correctness": 3,
"completeness": 2,
"accuracy": 3
},
"structure": {
"organization": 3,
"formatting": 2,
"usability": 3
},
"content_score": 2.7,
"structure_score": 2.7,
"overall_score": 5.4
}
},
"output_quality": {
"A": {
"score": 9,
"strengths": ["Complete solution", "Well-formatted", "All fields present"],
"weaknesses": ["Minor style inconsistency in header"]
},
"B": {
"score": 5,
"strengths": ["Readable output", "Correct basic structure"],
"weaknesses": ["Missing date field", "Formatting inconsistencies", "Partial data extraction"]
}
},
"expectation_results": {
"A": {
"passed": 4,
"total": 5,
"pass_rate": 0.80,
"details": [
{"text": "Output includes name", "passed": true}
]
},
"B": {
"passed": 3,
"total": 5,
"pass_rate": 0.60,
"details": [
{"text": "Output includes name", "passed": true}
]
}
}
}
analysis.json
Output from post-hoc analyzer. Located at <grading-dir>/analysis.json.
{
"comparison_summary": {
"winner": "A",
"winner_skill": "path/to/winner/skill",
"loser_skill": "path/to/loser/skill",
"comparator_reasoning": "Brief summary of why comparator chose winner"
},
"winner_strengths": [
"Clear step-by-step instructions for handling multi-page documents",
"Included validation script that caught formatting errors"
],
"loser_weaknesses": [
"Vague instruction 'process the document appropriately' led to inconsistent behavior",
"No script for validation, agent had to improvise"
],
"instruction_following": {
"winner": {
"score": 9,
"issues": ["Minor: skipped optional logging step"]
},
"loser": {
"score": 6,
"issues": [
"Did not use the skill's formatting template",
"Invented own approach instead of following step 3"
]
}
},
"improvement_suggestions": [
{
"priority": "high",
"category": "instructions",
"suggestion": "Replace 'process the document appropriately' with explicit steps",
"expected_impact": "Would eliminate ambiguity that caused inconsistent behavior"
}
],
"transcript_insights": {
"winner_execution_pattern": "Read skill -> Followed 5-step process -> Used validation script",
"loser_execution_pattern": "Read skill -> Unclear on approach -> Tried 3 different methods"
}
}