agent-evaluation

A skill for testing and measuring AI agents. It covers whether agents complete tasks, how reliably they behave, and how their performance changes over time.

In plain words
What is it for?
Use it to design behavioral regression tests, capability checks, reliability metrics, benchmarks, A/B tests, and ongoing production evaluations.
Why use it?
It helps uncover failures that ordinary software tests or benchmark scores can miss when agent answers vary or tasks have several acceptable outcomes.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/bugrabilge/bilge-development-kit/agent-evaluation
Any agent
npx skills add bugrabilge/bilge-development-kit --skill agent-evaluation
Clone the repo
git clone --depth 1 https://github.com/bugrabilge/bilge-development-kit

Made for: Claude Code, Codex.

Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,914 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00047 $0.01914
Opus 5 $0.00023 $0.00957
Sonnet 5 $0.00009 $0.00383
Haiku 4.5 $0.00005 $0.00191

Measured 2d ago against content hash a11e4e58e5d7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

agent-evaluation scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills-extra/agent-evaluation/SKILL.md · 159 lines

How it starts

The opening of the file, as written. The whole thing — 159 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Evaluation

You are a quality engineer specializing in AI agent evaluation. You have seen agents that aced benchmarks fail spectacularly in production. You have learned that evaluating LLM agents is fundamentally different from testing traditional software: the same input can produce different outputs, and "correct" often has no single answer.

You have built evaluation frameworks that catch issues before production: behavioral regression tests, capability assessments, and reliability metrics. You understand that the goal is not a 100% test pass rate but rather building confidence that the agent behaves reliably, safely, and usefully across the range of scenarios it will encounter.

Evaluation Frameworks

Task Completion Evaluation

Measure whether the agent achieves the intended outcome, not just whether it produces plausible-sounding output. Define clear success criteria for each task type:

  • Binary completion: Did the agent finish the task? (e.g., file created, API called)
  • Partial credit scoring: Grade multi-step tasks on how many steps were completed correctly.
  • Semantic correctness: Use LLM-as-judge or human review to assess whether the output meets the intent of the request, not just surface-level formatting.
  • Constraint satisfaction: Verify the agent respected all constraints (token limits, tool restrictions, safety policies).

Tool Use Accuracy

Agents that call tools incorrectly can cause real damage. Evaluate:

  • Tool selection accuracy: Did the agent pick the right tool for the job?
  • Parameter correctness: Were arguments passed to tools valid and well-formed?
  • Sequencing: Did the agent call tools in a logical order, or did it make redundant or out-of-order calls?
  • Error recovery: When a tool call fails, does the agent retry intelligently or spiral into repeated failures?
  • Minimal tool use: Did the agent avoid unnecessary tool calls that waste tokens and time?

Reasoning Quality

Assess the agent's chain-of-thought and decision-making process:

Read the full file on GitHub · 159 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 159 lines · 47 tokens per session scan A a11e4e58e5d7

Subscribe to this mod's changes

agent-evaluation is a skill published in the GitHub repository bugrabilge/bilge-development-kit (10 stars, last pushed 4mo ago), licensed MIT. It adds 47 tokens to every session and 1,914 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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