feat(pdf-reader): add skill for PDF text extraction fallback

Submitted by: https://github.com/divitkashyap

## What
Added  — a skill that automatically detects when an agent cannot read PDFs and provides text extraction using command-line tools with optional installation and user confirmation.

## Why
Many AI agents lack native PDF reading capability. When they encounter a PDF, they either:
- Fail to help the user
- Give generic responses about not being able to access PDF content

This skill intercepts that situation and provides a complete fallback workflow using standard tools (pdftotext, pdfplumber, pymupdf).

## How It Works
1. **Detection**: Monitors for agent statements like 'I cannot read PDFs', 'I don't have the ability to read PDFs', etc.
2. **Tool Detection**: Checks for available tools in priority order: pdftotext → pdfplumber → pymupdf
3. **Installation**: If no tool found, asks user permission with platform-specific install commands
4. **Extraction**: Extracts PDF text to /tmp/pdf_extracted.txt
5. **Continuation**: Reads extracted text and proceeds with original user task

## Tool Priority
1. **pdftotext** (poppler-utils) — Preferred, fastest, system-level tool
2. **pdfplumber** (Python) — Fallback if poppler not available
3. **pymupdf** (Python) — Alternative Python fallback

## Platform Support
- **macOS**: Homebrew (brew install poppler) or pip
- **Linux (Ubuntu/Debian)**: apt-get install poppler-utils or pip
- **Linux (Fedora/RHEL)**: dnf install poppler-utils or pip
- **Windows**: winget/chocolatey or pip

## Key Features
- Automatic detection of agent PDF limitation
- Multi-tool fallback strategy
- User confirmation before installation
- Platform-specific installation commands
- Layout preservation option (-layout flag)
- Page range extraction support (-f, -l flags)
- Error handling for encrypted/protected PDFs

## Example Triggers
- 'I cannot read PDFs'
- 'I don't have the ability to read PDFs'
- 'I can't access PDF content'
- 'PDF reading is not supported'

## Files
- skills/pdf-reader/SKILL.md — Complete skill with workflow
- README.md — Updated with new skill entry

## Validation
All 15 skills pass: python .claude/skills/pr-review/scripts/validate_skills.py ✅

Author: divitkashyap

README.md

@@ -23,6 +23,7 @@ Development skills for AI coding agents. Plug into your favorite AI coding tool
 | `minimax-xlsx` | Open, create, read, analyze, edit, or validate Excel/spreadsheet files (.xlsx, .xlsm, .csv, .tsv). Covers creating new xlsx from scratch via XML templates, reading and analyzing with pandas, editing existing files with zero format loss, formula recalculation, validation, and professional financial formatting. | Official |
 | `minimax-docx` | Professional DOCX document creation, editing, and formatting using OpenXML SDK (.NET). Three pipelines: create new documents from scratch, fill/edit content in existing documents, or apply template formatting with XSD validation gate-check. | Official |
 | `vision-analysis` | Analyze, describe, and extract information from images using vision AI models. Supports describe, OCR, UI mockup review, chart data extraction, and object detection. Powered by MiniMax VL API with OpenAI GPT-4V fallback. | Community |
+| `pdf-reader` | Automatically detect when an agent cannot read PDFs and provide text extraction fallback using command-line tools (pdftotext/poppler-utils) with automatic detection, optional installation with user confirmation, and multi-platform support (macOS, Linux, Windows). | Community |
 | `minimax-multimodal-toolkit` | Generate voice, music, video, and image content via MiniMax APIs — the unified entry for MiniMax multimodal use cases. Covers TTS (text-to-speech, voice cloning, voice design, multi-segment), music (songs, instrumentals), video (text-to-video, image-to-video, start-end frame, subject reference, templates, long-form multi-scene), image (text-to-image, image-to-image with character reference), and media processing (convert, concat, trim, extract) via FFmpeg. | Official |
 
 ## Installation

skills/pdf-reader/SKILL.md

@@ -0,0 +1,206 @@
+---
+name: pdf-reader
+description: >
+  Automatically handle PDF text extraction when an agent lacks native PDF reading capability.
+  Use when: an agent responds with phrases like "I cannot read PDFs", "I don't have the ability to
+  read PDFs", "I can't access PDF content", "PDF reading is not supported", or similar statements
+  indicating the agent cannot process PDF files directly.
+  This skill intercepts that situation and provides a fallback workflow to extract PDF text using
+  command-line tools (pdftotext/poppler-utils), with automatic detection and optional installation.
+  Triggers: any message where the agent states it cannot read PDFs or lacks PDF capability.
+license: MIT
+metadata:
+  version: "1.0"
+  category: document-processing
+  sources:
+    - poppler-utils (pdftotext)
+    - pdfplumber (Python alternative)
+  submitted_by: https://github.com/divitkashyap
+---
+
+# PDF Reader Skill
+
+Automatically detect when an agent cannot read PDFs and provide text extraction fallback using command-line tools with user confirmation for installation.
+
+## Workflow
+
+### Step 1: Detect PDF Reading Limitation
+
+When the agent states it cannot read PDFs (phrases like "I cannot read PDFs", "I don't have the ability to read PDFs", etc.), activate this skill automatically.
+
+### Step 2: Identify the Target PDF
+
+Extract the PDF file path from the user's original request. Confirm the file exists:
+
+```bash
+ls -la "/path/to/document.pdf"
+```
+
+### Step 3: Check for Available PDF Tools
+
+Check which PDF text extraction tools are available on the system:
+
+```bash
+# Check for pdftotext (poppler-utils)
+which pdftotext || echo "NOT_FOUND"
+
+# Check for pdfplumber (Python)
+python3 -c "import pdfplumber; print('FOUND')" 2>/dev/null || echo "NOT_FOUND"
+
+# Check for pymupdf
+python3 -c "import fitz; print('FOUND')" 2>/dev/null || echo "NOT_FOUND"
+```
+
+### Step 4: Tool Selection Priority
+
+Select the best available tool in this order:
+
+1. **`pdftotext`** (poppler-utils) - Preferred, fastest, system-level tool
+2. **`pdfplumber`** (Python) - Fallback if poppler not available
+3. **`pymupdf`** (Python) - Alternative Python fallback
+
+### Step 5: Installation (If Needed)
+
+If no tool is found, ask the user for permission to install:
+
+```
+I need to install a PDF text extraction tool to read this PDF. 
+
+Available options:
+1. pdftotext (poppler-utils) - Fast, system-level tool [Recommended]
+2. pdfplumber - Python library alternative
+
+Shall I proceed with installation? (y/n)
+```
+
+**Installation commands by platform:**
+
+**macOS:**
+```bash
+brew install poppler  # Installs pdftotext
+# OR
+pip3 install pdfplumber
+```
+
+**Linux (Ubuntu/Debian):**
+```bash
+sudo apt-get install poppler-utils
+# OR
+pip3 install pdfplumber
+```
+
+**Linux (Fedora/RHEL):**
+```bash
+sudo dnf install poppler-utils
+# OR
+pip3 install pdfplumber
+```
+
+**Windows:**
+```powershell
+# Use winget
+winget install pdftotext
+# OR
+pip install pdfplumber
+```
+
+### Step 6: Extract PDF Text
+
+Once a tool is available, extract text from the PDF:
+
+**Using pdftotext:**
+```bash
+pdftotext -layout "/path/to/document.pdf" /tmp/pdf_extracted.txt
+```
+
+**Using pdfplumber (Python):**
+```python
+import pdfplumber
+
+with pdfplumber.open("/path/to/document.pdf") as pdf:
+    text = ""
+    for page in pdf.pages:
+        page_text = page.extract_text()
+        if page_text:
+            text += page_text + "\n\n"
+
+with open("/tmp/pdf_extracted.txt", "w") as f:
+    f.write(text)
+```
+
+**Using pymupdf (Python):**
+```python
+import fitz
+
+doc = fitz.open("/path/to/document.pdf")
+text = ""
+for page in doc:
+    text += page.get_text() + "\n\n"
+doc.close()
+
+with open("/tmp/pdf_extracted.txt", "w") as f:
+    f.write(text)
+```
+
+### Step 7: Read Extracted Text
+
+Read the extracted text file and present it to the user:
+
+```bash
+cat /tmp/pdf_extracted.txt
+```
+
+### Step 8: Continue Original Task
+
+After extracting and presenting the PDF content, proceed with the user's original request using the extracted text as context.
+
+## Platform-Specific Notes
+
+### macOS
+
+- poppler-utils can be installed via Homebrew: `brew install poppler`
+- Python libraries work with system Python3 or pyenv
+
+### Linux
+
+- Most distributions have poppler-utils in their package managers
+- pdfplumber/pymupdf require pip installation
+
+### Windows
+
+- poppler binaries available from official poppler releases or via winget/chocolatey
+- Python libraries recommended for Windows: `pip install pdfplumber`
+
+## Common Errors and Solutions
+
+| Error | Cause | Solution |
+|-------|-------|----------|
+| `pdftotext: command not found` | poppler-utils not installed | Install via package manager or use Python alternative |
+| `Permission denied` | Output directory not writable | Use `/tmp/` for output |
+| `File not found` | Wrong PDF path | Verify path with `ls -la` |
+| `PDF extraction failed` | Encrypted/protected PDF | Inform user and suggest manual extraction |
+| `pdftotext: syntax error` | Malformed PDF | Try with `-raw` flag instead of `-layout` |
+
+## Alternative Flags for pdftotext
+
+```bash
+# Basic extraction
+pdftotext input.pdf output.txt
+
+# Preserve layout (default)
+pdftotext -layout input.pdf output.txt
+
+# Simple extraction (no layout)
+pdftotext -raw input.pdf output.txt
+
+# Extract specific pages
+pdftotext -f 1 -l 5 input.pdf output.txt
+
+# Extract to stdout
+pdftotext -  # Reads from stdin
+```
+
+## File Size Limits
+
+- For PDFs larger than 50MB, extract page ranges instead of entire document
+- Use `-f` and `-l` flags to process in chunks if needed