Download Pdf

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, so the safety profile is covered. The description adds meaningful behavior beyond that: the return value is a resource link rather than raw bytes, which matters for how the agent consumes the result. It does not cover permissions or failure modes (e.g. missing attachment).

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?

The key behavior and usage rationale are front-loaded in two short sentences, followed by an Args block. It is efficient, though the Args block restates parameter names already visible in the schema and could be trimmed to only the non-obvious semantics.

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?

An output schema exists, so return-value documentation is not required, and the description captures the resource-link behavior well. The gaps are the two library scoping parameters, which are unexplained despite 0% schema coverage, and the absence of any differentiation from the closely related save_pdf sibling.

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 description coverage is 0%, so the description must carry the parameter burden, and it partially does: it clarifies that item_key is the parent item (not the attachment) and explains attachment_key is for disambiguating multiple PDFs. However, library_id and library_type are undocumented in both schema and description, leaving half the parameters opaque.

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 states a specific action and resource: returning a PDF as a remote-safe MCP resource link, which is more precise than a generic 'download file'. It implicitly distinguishes itself from the fulltext-oriented siblings by framing itself as the fallback when the fulltext index is incomplete, though it never names a sibling such as get_item_fulltext or save_pdf directly.

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?

It gives a clear triggering condition: use it when Zotero's fulltext index is incomplete (e.g. books) and the PDF must be read directly with other tools. That is genuine when-to-use guidance that routes the agent away from the search/get_fulltext siblings, but no explicit when-not-to-use or named alternative is provided.

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