Eval Skills
AI Agent Skill unit testing framework. A framework-agnostic toolkit for discovering, scaffolding, selecting, evaluating, and reporting on AI skills. Use this...
Description
name: eval-skills description: >- AI Agent Skill unit testing framework. A framework-agnostic toolkit for discovering, scaffolding, selecting, evaluating, and reporting on AI skills. Use this skill to assess skill quality before production, compare candidate skills on the same benchmark, enforce quality gates in CI/CD, and generate human-readable evaluation reports. version: 0.1.0
eval-skills
AI Agent Skill unit testing framework — a framework-agnostic toolkit for discovering, scaffolding, selecting, evaluating, and reporting on AI skills.
This skill fills the L1 (Skill Unit Test) gap that LangSmith / DeepEval leave open: while those platforms focus on agent-level and trajectory-level evaluation (L2-L3), eval-skills targets the individual skill level, ensuring each building block meets quality standards before it ever enters an agent pipeline.
When to Use This Skill
- Before deploying a new skill to production — run
evalto verify it meets your quality gate. - When choosing between multiple candidate skills — run
selectto rank them on the same benchmark. - When a skill is upgraded — run
report diffto detect regressions. - In CI/CD — use
--exit-on-failto block merges that degrade skill quality. - When bootstrapping a new skill — run
createto generate a ready-to-fill skeleton.
Capabilities
1. Find Skills
Search for existing skills by keyword, tag, or adapter type.
eval-skills find \
--query "web search" \
--tag retrieval api \
--adapter http \
--min-completion 0.8 \
--skills-dir ./skills \
--limit 10
| Option | Description | Default |
|---|---|---|
-q, --query <string> |
Keyword search (matches name, description, tags) | — |
-t, --tag <tags...> |
Filter by tags (intersection: skill must have ALL specified tags) | — |
-a, --adapter <type> |
Filter by adapter type (http, subprocess, mcp) |
— |
--min-completion <rate> |
Minimum historical completion rate (0.0 ~ 1.0) | — |
--skills-dir <dir> |
Directory to scan for skill.json files |
./skills |
--limit <n> |
Maximum number of results | 20 |
Results are ranked by search relevance (when --query is provided) or by historical completion rate (descending).
2. Create Skills
Generate a skill skeleton from a template to bootstrap development.
eval-skills create \
--name my_api_skill \
--from-template http_request \
--output-dir ./skills \
--description "Fetches weather data from OpenWeather API"
| Option | Description | Default |
|---|---|---|
--name <name> |
Required. Skill name | — |
--from-template <tpl> |
Template type: http_request, python_script, mcp_tool |
http_request |
--output-dir <dir> |
Output directory | ./skills |
--description <text> |
Human-readable description embedded in skill.json |
— |
Generated file structure:
skills/my_api_skill/
skill.json # Skill metadata (id, schemas, adapter config)
adapter.config.json # Adapter-specific configuration
tests/
basic.eval.json # A starter benchmark with one sample task
skill.py # (python_script template only) JSON-RPC entrypoint
3. Evaluate Skills
Run benchmark evaluations against one or more skills. This is the core command.
eval-skills eval \
--skills ./skills/calculator/skill.json ./skills/search/ \
--benchmark coding-easy \
--concurrency 4 \
--timeout 30000 \
--retries 2 \
--runs 3 \
--evaluator exact \
--format json markdown html \
--output-dir ./reports \
--exit-on-fail --min-completion 0.8 \
--store ./eval-skills.db
| Option | Description | Default |
|---|---|---|
--skills <paths...> |
Required. Skill file(s) or directory(ies) | — |
--benchmark <id|path> |
Built-in benchmark ID or path to benchmark.json |
coding-easy |
--tasks <file> |
Custom tasks JSON file (replaces benchmark) | — |
--concurrency <n> |
Number of parallel task executions | 4 |
--timeout <ms> |
Per-task timeout in milliseconds | 30000 |
--retries <n> |
Retry count on task failure (with incremental backoff) | 0 |
--runs <n> |
Repeat evaluation N times for consistency scoring | 1 |
--evaluator <type> |
Default scorer type (see Scorer Types below) | exact |
--format <formats...> |
Output formats: json, markdown, html |
json markdown |
--output-dir <dir> |
Report output directory | ./reports |
--exit-on-fail |
Exit with code 1 if any skill falls below threshold | disabled |
--min-completion <rate> |
Threshold for --exit-on-fail |
0.7 |
--dry-run |
Validate configuration only; do not execute tasks | disabled |
--benchmarks-dir <dir> |
Directory containing built-in benchmarks | ./benchmarks |
--store <path> |
SQLite database path for persistent result storage | ./eval-skills.db |
-c, --config <path> |
Path to eval-skills.config.yaml |
auto-detected |
Evaluation flow:
- Load skills from
--skillspaths (supports both singleskill.jsonand directories) - Load benchmark tasks from
--benchmarkor--tasks - Build the cartesian product:
skills x tasks x runs - Execute all task items concurrently (controlled by
--concurrency, with timeout and retry) - Score each result using the appropriate scorer
- Aggregate into
SkillCompletionReportper skill - Write reports to
--output-dir
4. Select Skills
Filter and rank skills based on evaluation reports using a multi-dimensional strategy.
eval-skills select \
--from ./skills \
--reports ./reports/eval-result.json \
--strategy ./strategy.yaml \
--min-completion 0.8 \
--top-k 5 \
--output ./selected.json
| Option | Description | Default |
|---|---|---|
--from <path> |
Required. Candidate skills directory or JSON file | — |
--reports <file> |
Evaluation reports JSON file | — |
--strategy <file> |
SelectStrategy YAML/JSON file | built-in default |
--min-completion <rate> |
Override minimum completion rate filter | — |
--top-k <n> |
Return only the top K results | all |
--output <file> |
Write selected skills to file | stdout |
Selection pipeline: Filter (by completion rate, error rate, latency, adapter type, required tags) -> Score -> Rank (by compositeScore, completionRate, latency, or tokenCost) -> TopK
Example strategy.yaml:
filters:
minCompletionRate: 0.8
maxErrorRate: 0.1
maxLatencyP95Ms: 5000
adapterTypes: [http, subprocess]
requiredTags: [production-ready]
sortBy: compositeScore
order: desc
topK: 5
5. Run Pipeline
Execute the full end-to-end pipeline: Find -> Eval -> Select -> Report in a single command.
eval-skills run \
--query "math" \
--benchmark coding-easy \
--skills-dir ./skills \
--top-k 3 \
--min-completion 0.7 \
--format json markdown \
--output-dir ./reports
This command automates the entire process:
- Find — scans
--skills-dirand optionally filters by--query - Eval — evaluates all candidate skills against
--benchmark - Select — filters and ranks results using
--min-completion,--top-k, and optional--strategy - Report — generates output files in all requested
--formats
6. Generate & Compare Reports
Convert report format
eval-skills report convert \
--input ./reports/eval-result.json \
--format html \
--output ./reports/eval-result.html
Supported output formats: markdown, html.
Diff two reports (regression detection)
eval-skills report diff \
./reports/v1.json ./reports/v2.json \
--label-a "v1.0" --label-b "v2.0" \
--output ./reports/diff.md
Generates a side-by-side delta table per skill showing changes in completion rate, error rate, P95 latency, and composite score with directional arrows.
7. Initialize Project
eval-skills init --dir .
Creates the project scaffold:
eval-skills.config.yaml— global configurationskills/— directory for skill definitionsbenchmarks/— directory for benchmark filesreports/— directory for evaluation output
8. Manage Configuration
# List all current configuration values
eval-skills config list
# Get a specific value (supports dot notation)
eval-skills config get llm.model
# Set a value (persisted to ~/.eval-skills/config.yaml)
eval-skills config set concurrency 8
eval-skills config set llm.model gpt-4o
eval-skills config set llm.temperature 0
Configuration is resolved in priority order:
- CLI flags (highest priority)
eval-skills.config.yamlin current directory~/.eval-skills/config.yaml- Built-in defaults (
concurrency: 4,timeoutMs: 30000,outputDir: ./reports)
Scorer Types
Each task in a benchmark specifies an evaluator type. The scorer compares the skill's actual output against the expected output.
| Type | Aliases | Description | Score Range |
|---|---|---|---|
exact_match |
exact |
Strict equality comparison. Supports caseSensitive option. |
0 or 1 |
contains |
— | Checks for the presence of all specified keywords in the output. Partial credit: matched_keywords / total_keywords. |
0.0 ~ 1.0 |
json_schema |
schema |
Validates output against a JSON Schema (using Ajv). | 0 or 1 |
llm_judge |
— | Sends the output + expected rubric to an LLM (configurable model) for quality rating. | 0.0 ~ 1.0 |
custom |
— | Loads a custom scorer from expectedOutput.customScorerPath. |
0.0 ~ 1.0 |
Evaluation Metrics
Every evaluation produces a SkillCompletionReport with these metrics:
| Metric | Description | Formula |
|---|---|---|
| Completion Rate | Fraction of tasks that passed | pass_count / total_count |
| Partial Score | Mean score across all tasks | mean(task_scores) |
| Error Rate | Fraction of tasks that errored or timed out | (error_count + timeout_count) / total_count |
| Consistency Score | Stability across multiple runs (requires --runs >= 2) |
1 - stddev(per_run_completion_rates) |
| P50 / P95 / P99 Latency | Response time percentiles | Sorted percentile of latencyMs |
| Composite Score | Weighted overall quality score | 0.5 * CR + 0.2 * (1 - latP95_norm) + 0.3 * (1 - ER) |
Built-in Benchmarks
| ID | Domain | Tasks | Scoring | Description |
|---|---|---|---|---|
coding-easy |
coding | 20 | mean / exact_match | Math expressions, string reversal, palindrome detection |
skill-quality |
tool-use | 5 | mean / contains | Metadata completeness, description quality, structure checks |
web-search-basic |
web | 8 | mean / contains + schema | Factual queries, keyword verification, structured output validation |
gaia-v1 |
general | — | mean | Placeholder for GAIA benchmark Level 1 tasks |
toolbench-lite |
tool-use | — | mean | Placeholder for ToolBench single-tool scenarios |
Custom Benchmark
Create a benchmark.json file:
{
"id": "my-benchmark",
"name": "My Custom Benchmark",
"version": "1.0.0",
"domain": "general",
"scoringMethod": "mean",
"maxLatencyMs": 30000,
"metadata": { "source": "internal", "lastUpdated": "2026-02-28" },
"tasks": [
{
"id": "task_001",
"description": "Test basic addition",
"inputData": { "expression": "2+3" },
"expectedOutput": { "type": "exact", "value": "5" },
"evaluator": { "type": "exact" },
"timeoutMs": 10000,
"tags": ["math"]
},
{
"id": "task_002",
"description": "Test keyword presence",
"inputData": { "query": "TypeScript" },
"expectedOutput": { "type": "contains", "keywords": ["JavaScript", "Microsoft"] },
"evaluator": { "type": "contains", "caseSensitive": false },
"timeoutMs": 15000,
"tags": ["search"]
}
]
}
eval-skills eval --skills ./my-skill/ --benchmark ./my-benchmark.json
Adapter Types
Skills communicate through adapters. The adapter type is specified in skill.json via adapterType.
| Adapter | Protocol | How it works | Key config |
|---|---|---|---|
http |
REST POST | Sends POST { skillId, version, input } to skill.entrypoint. Supports Bearer / API-Key auth via env vars. |
baseUrl, authType, authTokenEnvKey |
subprocess |
JSON-RPC 2.0 over stdin/stdout | Spawns skill.entrypoint (e.g. python3 skill.py), writes JSON-RPC request to stdin, reads response from stdout. |
command, args |
mcp |
MCP Protocol | (Phase 2) Native Model Context Protocol integration via @modelcontextprotocol/sdk. |
— |
Workflow Examples
Evaluating a Single Skill
# 1. Create a skill skeleton
eval-skills create --name my_calc --from-template python_script
# 2. Implement your logic in skills/my_calc/skill.py
# 3. Run evaluation against the coding-easy benchmark
eval-skills eval \
--skills ./skills/my_calc/skill.json \
--benchmark coding-easy \
--runs 3 \
--format json markdown
# 4. Review the report
cat ./reports/eval-result-*.md
Comparing Multiple Candidate Skills
# 1. Discover candidates
eval-skills find --query "weather" --skills-dir ./skills
# 2. Evaluate all candidates on the same benchmark
eval-skills eval \
--skills ./skills/weather_v1 ./skills/weather_v2 ./skills/weather_v3 \
--benchmark web-search-basic \
--runs 3
# 3. Select the best
eval-skills select \
--from ./skills \
--reports ./reports/eval-result-*.json \
--min-completion 0.8 \
--top-k 2
# 4. Compare two versions
eval-skills report diff \
./reports/v1.json ./reports/v2.json \
--label-a "weather_v1" --label-b "weather_v2"
Full Pipeline (One Command)
eval-skills run \
--skills-dir ./skills \
--benchmark coding-easy \
--top-k 3 \
--min-completion 0.7 \
--format json markdown html \
--output-dir ./reports
CI/CD Quality Gate
# In your CI pipeline — fail the build if completion rate drops below 80%
eval-skills eval \
--skills ./skills/production_skill \
--benchmark coding-easy \
--exit-on-fail \
--min-completion 0.8 \
--format json
Regression Detection
# Compare today's evaluation against the baseline
eval-skills report diff \
./reports/baseline.json ./reports/latest.json \
--label-a "baseline" --label-b "latest" \
--output ./reports/regression-check.md
Best Practices
-
Always use
--runs 3or more when evaluating for production decisions. Single-run results can be noisy; the consistency score captures stability across runs. -
Use
--exit-on-failin CI/CD pipelines to enforce quality gates. Set--min-completionto your acceptable threshold (recommended: 0.8 for production skills). -
Create domain-specific custom benchmarks rather than relying solely on built-in ones. Your custom benchmark should reflect real-world inputs your skill will encounter.
-
Use
report diffafter every skill upgrade to catch regressions early. Compare the new evaluation against a saved baseline report. -
Use
--dry-runbefore long evaluations to validate your configuration (skill paths, benchmark resolution, task count) without actually executing tasks. -
Persist results with
--storeto track skill quality over time. The SQLite store enables historical trend queries. -
Start with
--concurrency 1when debugging a failing skill, then increase for production benchmarking. -
Tag your benchmark tasks to enable per-category analysis (e.g., filter by
math,string,edge-case).
Skill JSON Schema
Every skill must provide a skill.json that conforms to this structure:
{
"id": "my_skill_v1",
"name": "My Skill",
"version": "1.0.0",
"description": "Does something useful",
"tags": ["utility", "math"],
"inputSchema": {
"type": "object",
"properties": { "query": { "type": "string" } },
"required": ["query"]
},
"outputSchema": {
"type": "object",
"properties": { "result": { "type": "string" } }
},
"adapterType": "subprocess",
"entrypoint": "python3 skill.py",
"metadata": {
"author": "Your Name",
"license": "MIT",
"homepage": "https://github.com/you/my-skill"
}
}
Validation rules:
id: lowercase alphanumeric with_or-, non-emptyversion: semver format (X.Y.Z)adapterType: one ofhttp,subprocess,mcp,langchain,customentrypoint: non-empty string (URL for http, command for subprocess)
Global Options
These options are available on all commands:
| Option | Description |
|---|---|
-c, --config <path> |
Path to configuration file |
--json |
JSON output format (CI-friendly) |
--no-color |
Disable colored output |
-v, --verbose |
Verbose logging |
--version |
Show version |
-h, --help |
Show help |
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