get_pdf_link

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries full burden. It transparently states the tool returns a PDF URL if legally available, otherwise a note. However, it does not disclose potential failure modes (e.g., invalid DOI) or usage limits.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, each earning its place: first defines action and resource, second clarifies return value. No extraneous information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple tool with one parameter and no output schema, the description adequately explains what the tool does and returns. It could mention that only open-access articles are covered, but that is already implied in 'open-access PDF'.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the description includes the DOI parameter's purpose, but it does not add meaning beyond the schema's own description ('Article DOI, e.g. ...'). No additional formatting or usage context is provided.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses specific verb 'Find' and identifies the resource as 'open-access PDF for an article by DOI via Unpaywall'. It clearly states the return value (PDF URL or note), distinguishing it from sibling tools like get_abstract_details or get_author_profile.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage for retrieving an open-access PDF, but does not explicitly state when to use or avoid this tool relative to alternatives. No guidance on prerequisites or scenarios where the PDF might not be available beyond a generic note.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.