download_paper

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

No annotations are provided, so the description carries the full burden. It usefully discloses operational traits beyond the schema: downloads are slow and serialized ('one at a time'), and the WebVPN requirement. It omits failure/error behavior, whether files are overwritten, and any dependency on an authenticated session, even though the sibling check_session implies auth is a factor.

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?

Three tightly packed sentences, front-loaded with the core action and input forms; the example URL is high-value. Slight redundancy between 'slowly' and 'one at a time' keeps it from a 5.

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 download tool with no output schema, the description should indicate what is returned (e.g., saved file path or confirmation) and whether a valid WebVPN session is a precondition. It covers inputs and performance but leaves those two agent-relevant points unstated.

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 100%, so the schema already documents url ('WebVPN URL, publisher URL, or DOI'), filename, and output_dir. The description's phrasing of the accepted url forms duplicates the schema rather than extending it, so the baseline of 3 applies.

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?

States a specific verb (Download), resource (a single paywalled paper PDF), and the mechanism (Hainan University WebVPN). It also implicitly separates itself from the sibling download_papers via 'single' and 'one at a time'.

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?

Gives clear context for when it applies (single paywalled paper, via WebVPN, accepting WebVPN URL / publisher URL / DOI), which tells the agent what inputs qualify. It does not explicitly name download_papers as the alternative for batches, so the routing guidance stops short of 5.

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