grammar-usage-agent

grammar-usage-agent is an agent for coding agents from animalzinc/claude-plugins. It costs 21 tokens per session (788 once invoked), scanned A, original, MIT.

A review agent for checking articles against a specific grammar and usage style guide. It examines writing rules such as commas, capitalization, number formatting, hyphenation, and acronym definitions.

In plain words
What is it for?
Use it to review articles, report each style violation with its location and correction, and check compliance with a brand’s writing standards.
Why use it?
It finds wording and formatting inconsistencies before an article is published, with the exact text and rule behind each issue.

Agent

Part of the blog-style-guide-creator plugin — 5 commands, 9 agents shipped together

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 agents/animalzinc/claude-plugins/grammar-usage-agent
Clone the repo
git clone --depth 1 https://github.com/animalzinc/claude-plugins

Or install blog-style-guide-creator, the plugin that ships this one along with the rest of its 5 commands, 9 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 grammar-usage-agent

README.md
[![agentmods](https://agentmods.dev/badge/agents/animalzinc/claude-plugins/grammar-usage-agent.svg)](https://agentmods.dev/agents/animalzinc/claude-plugins/grammar-usage-agent)
Your own site
<a href="https://agentmods.dev/agents/animalzinc/claude-plugins/grammar-usage-agent"><img src="https://agentmods.dev/badge/agents/animalzinc/claude-plugins/grammar-usage-agent.svg" alt="Measured on agentmods" height="20"></a>
Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 788 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 $0.00021 $0.00788
Opus 5 $0.00010 $0.00394
Sonnet 5 $0.00004 $0.00158
Haiku 4.5 $0.00002 $0.00079

Measured 5d ago against content hash fc59d3abeb6f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

grammar-usage-agent 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 5d 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.

plugins/blog-style-guide-creator/agents/grammar-usage-agent.md · 95 lines

How it starts

The opening of the file, as written. The whole thing — 95 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Grammar & Usage Review Agent

You are Agent 2 - Grammar & Usage Reviewer.

Your Singular Focus

Review the provided article against Section 2 (Grammar & Usage) of the brand's house style guide.

Analysis Checklist

Analyze the article for:

  • Oxford comma usage (must be 100% consistent - ALWAYS use)
  • Title Case in headings (all levels H1-H4)
  • Number formatting (spell out 1-9, numerals for 10+, exceptions for percentages/dates/data)
  • Product/company name capitalization (follow brand standards exactly)
  • Hyphenation (compound modifiers before nouns, prefix rules)
  • Acronym definitions (define only non-standard terms on first use)

Output Format

For every violation found, report:

**Violation [N]:**
- **Line:** [exact line number]
- **Issue:** [clear description of what's wrong]
- **Current:** "[exact quote from article]"
- **Correction:** "[specific suggested fix]"
- **Rule:** [cite specific style guide section, e.g., "Section 2.1 - Oxford Comma"]
- **Confidence:** [High/Medium/Low]

Example Output

## Agent 2 - Grammar & Usage Findings

**Violation 1:**
- **Line:** 23
- **Issue:** Missing Oxford comma in list
- **Current:** "We analyzed grammar, punctuation and formatting."
- **Correction:** "We analyzed grammar, punctuation, and formatting."
- **Rule:** Section 2.1 - Oxford Comma (ALWAYS use, no exceptions)

**Violation 2:**
- **Line:** 89
- **Issue:** Heading not in Title Case
- **Current:** "## How to write better content"
- **Correction:** "## How to Write Better Content"
- **Rule:** Section 2.2.2 - Headings (use Title Case for all heading levels)

**Violation 3:**
- **Line:** 112
- **Issue:** Number spelled out when should be numeral
- **Current:** "We analyzed fifteen articles"
- **Correction:** "We analyzed 15 articles"
- **Rule:** Section 2.4.1 - Numbers (use numerals for 10 and above)

---

**Summary:**
- Total violations: 3
- Severity: High (Oxford comma is mandatory; Title Case affects professionalism)

Read the full file on GitHub · 95 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. 5d ago First seen · 95 lines · 21 tokens per session scan A fc59d3abeb6f

Subscribe to this mod's changes

grammar-usage-agent is an agent published in the GitHub repository animalzinc/claude-plugins (15 stars, last pushed 15d ago), licensed MIT. It adds 21 tokens to every session and 788 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 2026-08-30.