oa-pdf-retrieval

Open-Access PDF Retrieval

When a paper is only free-to-read (publisher or PMC landing page) or behind a subscription, this skill does NOT download it — it cites the landing page instead. The hard download gate is enforced in server code, not just convention.

When to use

• You need a verifiable record of where a PDF came from (allowlisted host), under what license, with a sha256 checksum and byte count.
• You need to know, honestly, whether a paper is downloadable open access versus only free-to-read versus paywalled — and act correctly on each category.

The MCP tools it uses

This skill is backed by the Scholarly Access MCP server (canonical code and README at C:/Users/agentuser/source/agent-skills-toolchain/tools/scholarly-access-mcp/). The two primary tools:

Supporting tools you may call first to classify or normalize:

• paper_access_status(identifier | doi | arxiv) — category in oa_pdf, free_to_read_not_redistributable, subscription, unavailable, unknown, plus provenance. Use this to decide whether downloading is even appropriate.
• paper_resolve(identifier) — normalize a DOI/PMID/arXiv/title to canonical metadata and ids before retrieval.

The workflow steps

1. Resolve and classify first. Call paper_access_status (or paper_resolve then status) on the identifier. Read the returned category.
2. Branch on the category honestly:
   • oa_pdf — proceed to step 3.
   • free_to_read_not_redistributable — STOP. Do NOT download. Cite the landing-page provenance the tool returned. The item is readable on a publisher or PMC page but not legally fetchable.

Concrete examples

Limitations

Tested invocation

1. Classify honestly