Source: google/agents-cli · Maintainer: Google · License: Apache-2.0 · Checked: 26 October 2026
What is the google-agents-cli-eval skill?
google-agents-cli-eval is an Agent Skill that teaches a coding agent how to evaluate an AI agent with the agents-cli command. It covers eval datasets, built-in and custom metrics, LLM-as-judge scoring, reading failures and the fix loop Google calls the Quality Flywheel.
It is one of seven skills in google/agents-cli, Google's "CLI and skills for building agents on Gemini platform." The SKILL.md description says it "Applies to any agents-cli project, whatever framework the agent is written in," and points agent code, deployment and scaffolding to their own skills.
As of 26 October 2026, its skills.sh page listed about 511,900 installs (snapshot, 26 October 2026). The SKILL.md metadata lists Google as author and version 1.11.0.
What does it do?
The SKILL.md assumes a scaffolded project, where a dataset and a custom metric already sit in tests/eval/ (Python) or eval/ (Go). Its advice is to run agents-cli eval run first and iterate from there.
The Quality Flywheel
Four stages, each with a default path the coding agent does itself and an opt-in command:
| Stage | Default | Opt-in command |
|---|---|---|
| 1. Prepare data | Edit tests/eval/datasets/basic-dataset.json, start with 1 to 2 cases |
agents-cli eval dataset synthesize (ADK) |
| 2. Run the eval | agents-cli eval run |
eval generate then eval grade |
| 3. Analyze failures | Read the latest results_<ts>.html or .json |
agents-cli eval analyze |
| 4. Optimize and fix | Edit prompts, tool descriptions or instructions | agents-cli eval optimize (ADK) |
After each fix, the agent runs agents-cli eval compare <prev>.json <new>.json to confirm the target metric improved without regressing others. The skill expects 5 to 10 or more iterations per case and says to keep a slice of cases out of the loop: "Hold cases back."
Choosing metrics
The skill maps goals to built-in metrics. multi_turn_task_success checks whether the agent achieved the user's goal, multi_turn_trajectory_quality judges the reasoning path, and multi_turn_tool_use_quality judges tool calls. Others include final_response_quality, hallucination, grounding, safety and final_response_match. Only the three multi-turn metrics accept multi-turn traces. agents-cli eval metric list shows them all, and Google's metric docs hold the definitions.
When no built-in fits, a YAML config file declares metrics_to_run plus a pool of custom_metrics: a prompt_template makes an LLM-judge metric, and a custom_function makes a Python metric. A metric defined in the pool runs only if it is also listed in metrics_to_run or passed with --metrics.
Fixing what fails
A table maps each low score to a change. A low multi_turn_tool_use_quality means fixing tool descriptions, parameter docstrings or instructions. A low hallucination score means tightening instructions to stay grounded in tool output. For tool checks, it recommends rubric-based metrics over hardcoded call sequences, because agents call helper tools in different orders.
Gotchas it covers
- The ADK
Appname must match the agent's directory, or you get "Session not found" errors. eval run,eval gradeandeval submitdefault to theglobalendpoint and don't inherit the project region; pass--regionfor data residency.- Models with thinking enabled may skip tool calls; force tool use with
tool_configset tomode="ANY". - Use a
before_agent_callbackto initialize session state and avoid aKeyErroron the first turn.
Seven reference files go deeper: dataset_schema.md, metrics-guide.md, user-simulation.md, builtin-tools-eval.md, advanced-commands.md, multimodal-eval.md and live-eval.md.
How do you install it?
The Getting Started guide lists Python 3.11+, uv and Node.js as prerequisites. The recommended install adds the CLI and all seven skills:
uvx google-agents-cli setup
Or install skills only, either the whole set or just this one (the command shown on skills.sh):
npx skills add google/agents-cli
npx skills add https://github.com/google/agents-cli --skill google-agents-cli-eval
The skill's metadata lists the agents-cli binary as a requirement, installed with uv tool install google-agents-cli. In Claude Code, run /skills to confirm the agents-cli skills are listed. Codex and Cursor read the same SKILL.md format; see Codex skills and Cursor skills.
How do you use it?
The skill loads when you ask to "run an evaluation", "evaluate my agent", "write an eval dataset", "analyze eval failures", "compare eval results" or "optimize agent", per its description. You can also call /google-agents-cli-eval in Claude Code. The workflow skill marks it mandatory before any eval run.
Example prompts (suggestions, not quotes from the repo):
Run the evals and paste the scores table. Don't change anything yet.Add three eval cases for refund requests, including one where the order ID is missing.multi_turn_tool_use_quality dropped after my last change. Compare the two results files and tell me why.Write a custom metric that fails any response longer than 120 words.Synthesize five multi-turn scenarios for an angry customer and grade them.
Google's Evaluation Guide covers the same commands for running evals by hand.
Tips and limits
From the SKILL.md, the repo docs and skills.sh, not from testing:
- Show the numbers. The skill's "Proving Your Work" section tells the agent to paste the scores table after each run and before deploy, since the exit code is always 0.
- Don't move the bar. Its shortcuts table rejects lowering the bar, skipping flaky cases or only editing expected outputs.
- Some commands are ADK only.
eval dataset synthesizeandeval optimizeload the agent through ADK; the rest of the loop is framework-agnostic. - Optimization costs. GEPA optimization "makes many LLM calls and can take a long time." The agent should run it once, and only when asked.
- Local code metrics run with your privileges. Python metrics run in-process by default; set
execution: "remote"to run them in the Gemini platform sandbox instead. - Security audits. On skills.sh, Gen Agent Trust Hub rated it Pass with risk level Safe (22 October 2026); its report notes that local custom metrics need trusted code and that traces can carry indirect prompt injection. Socket (20 October 2026) and Snyk (risk level Low, 20 October 2026) rated it Pass.
Under Apache 2.0 you can copy and modify the skill as long as you keep the license and notices and mark files you change.
Save it in your Kipt library
In Kipt, open Skills and paste the skill's GitHub folder link to import it with its seven reference files, or paste the repo link and pick from the list of all seven agents-cli skills. You can also drop the folder or a .zip. Your skills live in your own private GitHub repo and install into Claude Code or Codex with one command:
npx skills add https://github.com/<you>/<repo>.git --all -g
Kipt is not affiliated with Google.
Similar skills
- google-agents-cli-workflow skill: the lifecycle that makes eval Phase 4.
- google-agents-cli-adk-code skill: where most fixes land, in the agent code.
- google-agents-cli-deploy skill: asks for your eval scores before deploying.
- google-agents-cli-observability skill: production traces that feed new eval cases.
- Verification before completion skill: the same "show evidence" habit for general coding.
- Property-based testing skill: deterministic testing for the non-LLM code around your agent.