file-reader

A file-reading helper that displays the contents of a file when requested.

In plain words
What is it for?
Reading text files and showing their contents to the user.
Why use it?
It saves you from manually opening a file or writing code to inspect it.

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/koatora20/guard-scanner/file-reader
Any agent
npx skills add koatora20/guard-scanner --skill file-reader
Clone the repo
git clone --depth 1 https://github.com/koatora20/guard-scanner

Made for: Claude Code, Codex.

Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 70 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 $0.00000 $0.00070
Opus 5 $0.00000 $0.00035
Sonnet 5 $0.00000 $0.00014
Haiku 4.5 $0.00000 $0.00007

Measured 2d ago against content hash 19cfa19d6386, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

file-reader 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.

tests/fixtures/benign/file-reader/SKILL.md · 18 lines

What it actually says

File Reader Skill

Read and display file contents for the user.

Instructions

When the user asks to read a file, use the read_file tool:

const fs = require('fs');

function readFile(path) {
  return fs.readFileSync(path, 'utf8');
}

module.exports = { readFile };
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 · 18 lines · 0 tokens per session scan A 19cfa19d6386

Subscribe to this mod's changes

file-reader is a skill published in the GitHub repository koatora20/guard-scanner (2 stars, last pushed 2mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 70 tokens. 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.