split-pdf

name: split-pdf description: Download, split, and deeply read academic PDFs. Use when asked to read, review, or summarize an academic paper. Splits PDFs into 4-page chunks, reads them in small batches, and produces structured reading notes — avoiding context window crashes and shallow comprehension. allowed-tools: Bash(python*), Bash(pip*), Bash(curl*), Bash(wget*), Bash(mkdir*), Bash(ls*), Read, Write, Edit, WebSearch, WebFetch argument-hint: [pdf-path-or-search-query]

Split-PDF: Download, Split, and Deep-Read Academic Papers

CRITICAL RULE: Never read a full PDF. Never. Only read the 4-page split files, and only 3 splits at a time (~12 pages). Reading a full PDF will either crash the session with an unrecoverable "prompt too long" error — destroying all context — or produce shallow, hallucinated output. There are no exceptions.

When This Skill Is Invoked

The user wants you to read, review, or summarize an academic paper. The input is either:

• A file path to a local PDF (e.g., ./articles/smith_2024.pdf)
• A search query or paper title (e.g., "Gentzkow Shapiro Sinkinson 2014 competition newspapers")

Important: You cannot search for a paper you don't know exists. The user MUST provide either a file path or a specific search query — an author name, a title, keywords, a year, or some combination that identifies the paper. If the user invokes this skill without specifying what paper to read, ask them. Do not guess.

Step 1: Acquire the PDF

If a local file path is provided:

• Verify the file exists
• If the file is NOT already inside ./articles/, copy it there (do not move — preserve the original location)
• Proceed to Step 2

If a search query or paper title is provided:

1. Use WebSearch to find the paper
2. Use WebFetch or Bash (curl/wget) to download the PDF
3. Save it to ./articles/ in the project directory (create the directory if needed)
4. Proceed to Step 2

CRITICAL: Always preserve the original PDF. The downloaded or provided PDF in ./articles/ must NEVER be deleted, moved, or overwritten at any point in this workflow. The split files are derivatives — the original is the permanent artifact.

Step 2: Split the PDF

Create a subdirectory for the splits and run the splitting script:

from PyPDF2 import PdfReader, PdfWriter
import os, sys

def split_pdf(input_path, output_dir, pages_per_chunk=4):
    os.makedirs(output_dir, exist_ok=True)
    reader = PdfReader(input_path)
    total = len(reader.pages)
    prefix = os.path.splitext(os.path.basename(input_path))[0]

    for start in range(0, total, pages_per_chunk):
        end = min(start + pages_per_chunk, total)
        writer = PdfWriter()
        for i in range(start, end):
            writer.add_page(reader.pages[i])

        out_name = f"{prefix}_pp{start+1}-{end}.pdf"
        out_path = os.path.join(output_dir, out_name)
        with open(out_path, "wb") as f:
            writer.write(f)

    print(f"Split {total} pages into {-(-total // pages_per_chunk)} chunks in {output_dir}")

Directory convention:

articles/
├── smith_2024.pdf                    # original PDF — NEVER DELETE THIS
└── split_smith_2024/                 # split subdirectory
    ├── smith_2024_pp1-4.pdf
    ├── smith_2024_pp5-8.pdf
    └── ...

If PyPDF2 is not installed, install it: pip install PyPDF2

Step 2.5: Triage Gate (First Split Only)

Before committing to a full read, triage the paper from its first split (pages 1-4).

Read only the first split file (abstract + introduction). Then make a relevance judgment:

Triage criteria — score relative to your study [defined in study-parameters.md]:

• 5 = ESSENTIAL: Directly studies your core research question
• 4 = HIGH: Studies closely related mechanisms or institutional context
• 3 = MEDIUM: Important background context
• 2 = LOW: Tangentially related
• 1 = SKIP: Not relevant enough to cite

Step 3: Read Continuously in Batches of 3 Splits

Read exactly 3 split files at a time (~12 pages). After each batch:

1. Read the 3 split PDFs using the Read tool
2. Update the running notes file (notes.md in the split subdirectory)
3. Continue immediately to the next batch — do NOT pause or ask for permission

CONTINUOUS MODE: Read all batches without stopping. The only pause point is AFTER all splits are read, when the notes file is finalized.

Step 4: Structured Extraction

As you read, collect information along these dimensions and write them into notes.md:

1. Research question — What is the paper asking and why does it matter?
2. Audience — Which sub-community of researchers cares about this?
3. Data — What data do they use? Unit of observation? Sample size? Time period?
4. Findings — What are the main results? Key coefficient estimates and standard errors?
5. Contributions — What is learned from this exercise that we didn't know before?
6. Replication feasibility — Is the data publicly available? Replication archive?

Methodology — CONDITIONAL extraction:

7. Method/ID strategy — ONLY extract if the paper uses a method relevant to your study (see study-parameters.md for your method)
8. Connection to your study — How does this paper's question, data, or findings relate to your research?

The Notes File

Output is notes.md in the split subdirectory:

articles/split_smith_2024/notes.md

Updated incrementally after each batch. By the time all splits are read, notes should contain specific data sources, variable names, sample sizes, coefficient estimates, and standard errors.

When NOT to Split

• Papers shorter than ~15 pages: read directly (still use the Read tool, not Bash)
• Policy briefs or non-technical documents: a rough summary is fine
• Triage only: read just the first split (pages 1-4)