mcpbeat

Behavioral Evals

google-gemini/behavioral-evals

Guidance for creating, running, fixing, and promoting behavioral evaluations. Use when verifying agent decision logic, debugging failures, debugging prompt steering, or adding workspace regression tests.

5k tokens
context cost
the whole folder, loaded on every use
7
files
instructions only
0
copies elsewhere
how many repositories repackaged it
106350
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository
npx skills add https://github.com/google-gemini/gemini-cli --skill behavioral-evals

What comes with it

15 723 bytes besides the instruction
assets/interactive_eval.ts.txt
assets/standard_eval.ts.txt
references/creating.md
references/fixing.md
references/promoting.md
references/running.md

The instruction itself

8 sections, as written by the author

Behavioral Evals

Overview

Behavioral evaluations (evals) are tests that validate the agent's decision-making (e.g., tool choice) rather than pure functionality. They are critical for verifying prompt changes, debugging steerability, and preventing regressions.

> [!NOTE]

> Single Source of Truth: For core concepts, policies, running tests, and general best practices, always refer to evals/README.md.


🔄 Workflow Decision Tree

  • Does a prompt/tool change need validation?
  • *No* -> Normal integration tests.
  • *Yes* -> Continue below.
  • Is it UI/Interaction heavy?
  • *Yes* -> Use appEvalTest (AppRig). See creating.md.
  • *No* -> Use evalTest (TestRig). See creating.md.
  • Is it a new test?
  • *Yes* -> Set policy to USUALLY_PASSES.
  • *No* -> ALWAYS_PASSES (locks in regression).
  • Are you fixing a failure or promoting a test?
  • *Fixing* -> See fixing.md.
  • *Promoting* -> See promoting.md.

📋 Quick Checklist

1. Setup Workspace

Seed the workspace with necessary files using the files object to simulate a realistic scenario (e.g., NodeJS project with package.json).

  • *Details in creating.md*

2. Write Assertions

Audit agent decisions using rig.setBreakpoint() (AppRig only) or index verification on rig.readToolLogs().

  • *Details in creating.md*

3. Verify

Run single tests locally with Vitest. Confirm stability locally before relying on CI workflows.

  • *See evals/README.md for running commands.*

📦 Bundled Resources

Detailed procedural guides:

  • creating.md: Assertion strategies, Rig selection, Mock MCPs.
  • fixing.md: Step-by-step automated investigation, architecture diagnosis guidelines.
  • promoting.md: Candidate identification criteria and threshold guidelines.

How to use it

Copy the folder

Take google-gemini/behavioral-evals from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.