description: Extract text and tables from PDF files, fill forms, merge documents. Use when working with PDF files or when the user mentions PDFs, forms, or document extraction.

description: Analyze Excel spreadsheets, create pivot tables, generate charts. Use when analyzing Excel files, spreadsheets, tabular data, or .xlsx files.

description: Generate descriptive commit messages by analyzing git diffs. Use when the user asks for help writing commit messages or reviewing staged changes.

description: Helps with documents

description: Processes data

description: Does stuff with files

pdf/
├── SKILL.md              # Main instructions (loaded when triggered)
├── FORMS.md              # Form-filling guide (loaded as needed)
├── reference.md          # API reference (loaded as needed)
├── examples.md           # Usage examples (loaded as needed)
└── scripts/
    ├── analyze_form.py   # Utility script (executed, not loaded)
    ├── fill_form.py      # Form filling script
    └── validate.py       # Validation script

---
name: PDF Processing
description: Extracts text and tables from PDF files, fills forms, and merges documents. Use when working with PDF files or when the user mentions PDFs, forms, or document extraction.
---

import pdfplumber
with pdfplumber.open("file.pdf") as pdf:
    text = pdf.pages[0].extract_text()

Claude loads FORMS.md, REFERENCE.md, or EXAMPLES.md only when needed.

bigquery-skill/
├── SKILL.md (overview and navigation)
└── reference/
    ├── finance.md (revenue, billing metrics)
    ├── sales.md (opportunities, pipeline)
    ├── product.md (API usage, features)
    └── marketing.md (campaigns, attribution)

undefined

grep -i "revenue" reference/finance.md
grep -i "pipeline" reference/sales.md
grep -i "api usage" reference/product.md

undefined

undefined

Claude reads REDLINING.md or OOXML.md only when the user needs those features.

undefined

**Good example: One level deep**:

```markdown  theme={null}

undefined

undefined

Claude can then read the complete file or jump to specific sections as needed.

For details on how this filesystem-based architecture enables progressive disclosure, see the [Runtime environment](#runtime-environment) section in the Advanced section below.

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Research Progress:
- [ ] Step 1: Read all source documents
- [ ] Step 2: Identify key themes
- [ ] Step 3: Cross-reference claims
- [ ] Step 4: Create structured summary
- [ ] Step 5: Verify citations

This example shows how workflows apply to analysis tasks that don't require code. The checklist pattern works for any complex, multi-step process.

**Example 2: PDF form filling workflow** (for Skills with code):

````markdown  theme={null}

Task Progress:
- [ ] Step 1: Analyze the form (run analyze_form.py)
- [ ] Step 2: Create field mapping (edit fields.json)
- [ ] Step 3: Validate mapping (run validate_fields.py)
- [ ] Step 4: Fill the form (run fill_form.py)
- [ ] Step 5: Verify output (run verify_output.py)

Clear steps prevent Claude from skipping critical validation. The checklist helps both Claude and you track progress through multi-step workflows.

undefined

This shows the validation loop pattern using reference documents instead of scripts. The "validator" is STYLE\_GUIDE.md, and Claude performs the check by reading and comparing.

**Example 2: Document editing process** (for Skills with code):

```markdown  theme={null}

The validation loop catches errors early.

If you're doing this before August 2025, use the old API.
After August 2025, use the new API.

undefined

undefined

undefined

undefined

undefined

undefined

Adjust sections as needed for the specific analysis type.

undefined

feat(auth): implement JWT-based authentication

Add login endpoint and token validation middleware

fix(reports): correct date formatting in timezone conversion

Use UTC timestamps consistently across report generation

chore: update dependencies and refactor error handling

- Upgrade lodash to 4.17.21
- Standardize error response format across endpoints

Examples help Claude understand the desired style and level of detail more clearly than descriptions alone.

undefined

<Tip>
  If workflows become large or complicated with many steps, consider pushing them into separate files and tell Claude to read the appropriate file based on the task at hand.
</Tip>

{
  "skills": ["pdf-processing"],
  "query": "Extract all text from this PDF file and save it to output.txt",
  "files": ["test-files/document.pdf"],
  "expected_behavior": [
    "Successfully reads the PDF file using an appropriate PDF processing library or command-line tool",
    "Extracts text content from all pages in the document without missing any pages",
    "Saves the extracted text to a file named output.txt in a clear, readable format"
  ]
}

**Bad example: Too many choices** (confusing):
"You can use pypdf, or pdfplumber, or PyMuPDF, or pdf2image, or..."

**Good example: Provide a default** (with escape hatch):
"Use pdfplumber for text extraction:
```python
import pdfplumber
```

For scanned PDFs requiring OCR, use pdf2image with pytesseract instead."

def process_file(path):
    """Process a file, creating it if it doesn't exist."""
    try:
        with open(path) as f:
            return f.read()
    except FileNotFoundError:
        # Create file with default content instead of failing
        print(f"File {path} not found, creating default")
        with open(path, 'w') as f:
            f.write('')
        return ''
    except PermissionError:
        # Provide alternative instead of failing
        print(f"Cannot access {path}, using default")
        return ''

def process_file(path):
    # Just fail and let Claude figure it out
    return open(path).read()

undefined

**Bad example: Magic numbers**:

```python  theme={null}
TIMEOUT = 47  # Why 47?
RETRIES = 5   # Why 5?

undefined

python scripts/analyze_form.py input.pdf > fields.json

{
  "field_name": {"type": "text", "x": 100, "y": 200},
  "signature": {"type": "sig", "x": 150, "y": 500}
}

python scripts/validate_boxes.py fields.json

**fill_form.py**: Apply field values to PDF

```bash
python scripts/fill_form.py input.pdf fields.json output.pdf

undefined

undefined

<Note>
  In this example, you'd need to write the `pdf_to_images.py` script.
</Note>

Claude's vision capabilities help understand layouts and structures.

bigquery-skill/
├── SKILL.md (overview, points to reference files)
└── reference/
    ├── finance.md (revenue metrics)
    ├── sales.md (pipeline data)
    └── product.md (usage analytics)

Use the BigQuery:bigquery_schema tool to retrieve table schemas.
Use the GitHub:create_issue tool to create issues.

**Bad example: Assumes installation**:
"Use the pdf library to process the file."

**Good example: Explicit about dependencies**:
"Install required package: `pip install pypdf`

Then use it:
```python
from pypdf import PdfReader
reader = PdfReader("file.pdf")
```"