surrogate-verifier

surrogate-verifier is a skill for Claude Code from Mathews-Tom/armory. It costs 56 tokens per session (1,887 once invoked), scanned A, original, MIT.

A verifier that creates test assertions and failure explanations for agent skill packages from a skill definition and task prompt. It keeps the verifier separate from the skill generator's reasoning to reduce biased checks.

In plain words
What is it for?
Use it to generate assertions, check skill outputs, and diagnose failures in a skill package.
Why use it?
It helps find whether a skill's output meets its intended requirements rather than relying only on the generator's own explanation.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the armory plugin — 85 skills shipped together

Good fit Use it to generate assertions, check skill outputs, and diagnose failures in a skill package.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/mathews-tom/armory/surrogate-verifier
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.

Any agent
npx skills add Mathews-Tom/armory --skill surrogate-verifier
Clone the repo
git clone --depth 1 https://github.com/Mathews-Tom/armory

Made for: Claude Code.

Or install armory, the plugin that ships this one along with the rest of its 85 skills.

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 surrogate-verifier

README.md
[![agentmods](https://agentmods.dev/badge/skills/mathews-tom/armory/surrogate-verifier.svg)](https://agentmods.dev/skills/mathews-tom/armory/surrogate-verifier)
Your own site
<a href="https://agentmods.dev/skills/mathews-tom/armory/surrogate-verifier"><img src="https://agentmods.dev/badge/skills/mathews-tom/armory/surrogate-verifier.svg" alt="Measured on agentmods" height="20"></a>
Per session 56 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,887 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00056 $0.01887
Opus 5 $0.00028 $0.00944
Sonnet 5 $0.00011 $0.00377
Haiku 4.5 $0.00006 $0.00189

Measured 3d ago against content hash 33a2253b985e, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

surrogate-verifier 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 3d 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/surrogate-verifier/SKILL.md · 197 lines

How it starts

The opening of the file, as written. The whole thing — 197 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Surrogate Verifier

Generate structured test assertions and failure diagnostics for skill packages through information-isolated verification. The verifier operates without access to the skill generator's reasoning — it sees only the skill definition, a task prompt, and the output artifacts. This isolation prevents confirmation bias and is the single largest contributor to skill quality in co-evolutionary generation (+30pp per EvoSkills).

Reference Files

File Contents Load When
references/assertion-patterns.md Assertion catalog by skill category with weight guidance Always
references/diagnostic-templates.md Failure diagnostic templates with root-cause categories When producing failure reports

Information Isolation Protocol

This is the most critical constraint. Violating isolation degrades verification quality.

The verifier MUST NOT access:

  • The generator's conversation history or reasoning chain
  • Prior evolution iterations or refinement context
  • The generator's internal notes or decision rationale
  • Any context beyond what is explicitly listed below

The verifier receives ONLY:

  1. The skill's SKILL.md content (the definition file)
  2. One or more task prompts representing intended use
  3. The skill's output (when diagnosing failures)
  4. The assertion results from scripts/eval_assertions.py (when diagnosing)

Implementation: When invoked by the test-engineer agent, this skill MUST be loaded into a separate Agent spawn using isolation: "worktree" or at minimum a fresh session with no shared context. The invoking agent passes artifacts as explicit text, not as conversation references.

Workflow

Mode 1: Assertion Generation

Read the full file on GitHub · 197 lines

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 3d ago First seen · 197 lines · 56 tokens per session scan A 33a2253b985e

Subscribe to this mod's changes

surrogate-verifier is a skill published in the GitHub repository Mathews-Tom/armory (316 stars, last pushed 2d ago), licensed MIT. It adds 56 tokens to every session and 1,887 once invoked, about $0.0003 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 2026-09-05.