Agent skill · research science · affaan-m
agent-eval
Head-to-head comparison of coding agents (Claude Code, Aider, Codex, etc.) on custom tasks with pass rate, cost, time, and consistency metrics. Use when choosing between coding agents, or when a change to an agent setup needs measured pass rate, cost, and time rather than an impression.
Why this skill is useful
Provides a structured framework for evaluating coding agents with specific metrics and reproducibility that the AI wouldn't generate on its own.
What it needs
Requires bash, grep installed locally. About 3k tokens when loaded. Last updated 2026-08-06. 238,342 stars on the source repository.
What this skill does
Agent Eval Skill A lightweight CLI tool for comparing coding agents head-to-head on reproducible tasks. Every "which coding agent is best?" comparison runs on vibes — this tool systematizes it. When to Activate Comparing coding agents (Claude Code, Aider, Codex, etc.) on your own codebase Measuring agent performance before adopting a new tool or model Running regression checks when an agent updates its model or tooling Producing data-backed agent selection decisions for a team Installation Note: Install agent-eval from its repository after reviewing the source. Core Concepts YAML Task Definitions Define tasks declaratively. Each task specifies what to do, which files to touch, and how to judge success: Git Worktree Isolation Each agent run gets its own git worktree — no Docker required. This provides reproducibility isolation so agents cannot interfere with each other or corrupt the base repo. Metrics Collected Metric What It Measures -------- ----------------- Pass rate Did the agent produce code that passes the judge? Cost API spend per task (when available) Time Wall-clock seconds to completion Consistency Pass rate across repeated runs (e.g., 3/3 = 100%) Workflow 1. Define Tasks Create a tasks/ directory with YAML files, one per task: 2. Run Agents Execute agents against your tasks: Each run: 1. Creates a fresh git worktree from the specified commit 2. Hands the prompt to the agent 3. Runs the judge criteria 4. Records pass/fail, cost, and time 3. …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills affaan-m/agent-eval--c47b55