prd-testability-judge

prd-testability-judge is an agent for Claude Code from closedloop-ai/claude-plugins. It costs 17 tokens per session (2,250 once invoked), scanned A, original, Apache-2.0.

A review tool that checks whether a PRD's acceptance criteria can be tested clearly and objectively. It looks for precise outcomes, measurable success metrics, and coverage of error cases.

In plain words
What is it for?
Use it to review user stories and acceptance criteria for observable results, unambiguous wording, measurable baselines, and missing edge cases.
Why use it?
It helps prevent vague requirements such as “works well” or “is easy to use,” which make it difficult to write reliable tests or agree that a feature is complete.

Agent for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: model in frontmatter.

Part of the judges plugin — 3 skills, 22 agents shipped together

Good fit Use it to review user stories and acceptance criteria for observable results, unambiguous wording, measurable baselines, and missing edge cases.

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Install with agentmods
npx agentmods add agents/closedloop-ai/claude-plugins/prd-testability-judge
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.

Clone the repo
git clone --depth 1 https://github.com/closedloop-ai/claude-plugins

Made for: Claude Code.

Or install judges, the plugin that ships this one along with the rest of its 3 skills, 22 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for prd-testability-judge

README.md
[![agentmods](https://agentmods.dev/badge/agents/closedloop-ai/claude-plugins/prd-testability-judge.svg)](https://agentmods.dev/agents/closedloop-ai/claude-plugins/prd-testability-judge)
Your own site
<a href="https://agentmods.dev/agents/closedloop-ai/claude-plugins/prd-testability-judge"><img src="https://agentmods.dev/badge/agents/closedloop-ai/claude-plugins/prd-testability-judge.svg" alt="Measured on agentmods" height="20"></a>
Per session 17 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,250 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00017 $0.02250
Opus 5 $0.00009 $0.01125
Sonnet 5 $0.00003 $0.00450
Haiku 4.5 $0.00002 $0.00225

Measured today against content hash c76c1f84bab9, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

prd-testability-judge 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 today.

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.

plugins/judges/agents/prd-testability-judge.md · 187 lines

How it starts

The opening of the file, as written. The whole thing — 187 lines — stays where its author put it; the contents beside it link to each section on GitHub.

PRD Testability Judge

  • Verifying that acceptance criteria are testable and unambiguous (GWT format is preferred but declarative bullets with clear, verifiable outcomes are also accepted)
  • Identifying vague, subjective, or unmeasurable qualifiers that prevent objective test authorship
  • Ensuring success metrics include observable baselines that can be measured against
  • Detecting user stories that lack edge-case or error-path coverage, leaving test plans incomplete

Your task is to analyze a PRD and produce a CaseScore JSON object. You do NOT rewrite the plan — you identify and report findings.

<analysis_instructions> Wrap all analytical thinking in <thinking> tags before producing your final JSON output.

Step 1: Locate and Read the PRD

Read $CLOSEDLOOP_WORKDIR/judge-input.json first. Parse source_of_truth, then read the mapped primary_artifact and supporting_artifacts in that exact ID order. Treat the primary artifact as the PRD or Feature document under evaluation and supporting descriptors as source-of-truth requirement evidence. Use legacy $CLOSEDLOOP_WORKDIR/prd.md only when judge-input.json is absent or invalid and the run explicitly indicates a one-run legacy fallback.

If neither the mapped artifact nor an explicit legacy fallback is readable, output a CaseScore JSON with final_status: 3 (error) and a note in the justification.

Step 2: Extract Acceptance Criteria and User Stories

  1. Identify all User Stories (labeled US-### or similar patterns).
  2. For each user story, collect all acceptance criteria (ACs) listed under it.
  3. Identify the Success Metrics section (if present) and its rows.

Step 3: Apply the Four Analysis Rules

Rule 1 — Testability Verification (severity: major)

For each AC across all user stories, assess whether it is testable — i.e., whether a QA engineer could write an unambiguous test for it without guessing at intent.

Read the full file on GitHub · 187 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. today First seen · 187 lines · 17 tokens per session scan A c76c1f84bab9

Subscribe to this mod's changes

prd-testability-judge is an agent published in the GitHub repository closedloop-ai/claude-plugins (103 stars, last pushed yesterday), licensed Apache-2.0. It adds 17 tokens to every session and 2,250 once invoked, about $0.0001 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 2026-09-07.