# File Reader

> Read, preview, and summarize text-based files — source code, configs, logs, data files, and plain text documents. Use when the user asks to read, inspect, or summarize local .txt, .md, .json, .yaml, .csv, .log, or source code files.

- Skill: `ymx10086/file-reader` (Agent Skill)
- Install (CLI): `npx skillmds@latest add ymx10086/file-reader`
- Raw SKILL.md: https://api.skillmd.com/api/skills/ymx10086/file-reader/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Data & Analytics
- Author: ymx10086 (https://skillmd.com/u/ymx10086)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/ymx10086/file-reader

---

# File Reader Toolbox

Use this skill when the user asks to read or summarize local text-based files. PDFs, Office documents, images, audio, and video are out of scope for this skill and should be handled by their dedicated skills/tools.

## Quick Type Check

Use a type probe before reading:

```bash
file -b --mime-type "/path/to/file"
```

If the file is large, avoid dumping the whole content; extract a small, relevant portion and summarize.

## Text-Based Files (use read_file)

Preferred for: `.txt`, `.md`, `.json`, `.yaml/.yml`, `.csv/.tsv`, `.log`, `.sql`, `ini`, `toml`, `py`, `js`, `html`, `xml` source code.

Steps:

1. Use `read_file` to fetch content.
2. Summarize key sections or show the relevant slice requested by the user.
3. For JSON/YAML, list top-level keys and important fields.
4. For CSV/TSV, show header + first few rows, then summarize columns.

## Large Logs

If the file is huge, use a tail window:

```bash
tail -n 200 "/path/to/file.log"
```

Summarize the last errors/warnings and notable patterns.

## Out of Scope

Do not handle the following in this skill (they are covered by other skills):

- PDF
- Office (docx/xlsx/pptx)
- Images
- Audio/Video

## Safety and Behavior

- Never execute untrusted files.
- Prefer reading the smallest portion necessary.
- If a tool is missing, explain the limitation and ask the user for an alternate format.