fetch

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

No annotations are provided, so the description carries the burden. It discloses that the copy is stored privately and that held papers cost nothing, which is useful behavioral context. However, it doesn't mention what happens if the paper is not open-access, whether the operation is read-only or creates a record, or any rate limits or auth requirements.

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?

One sentence, front-loaded with the verb and resource, and the parenthetical adds a key cost detail without bloat. Every word earns its place.

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?

The tool has an output schema, so return values are covered elsewhere. But with no annotations, no parameter semantics, and no mention of failure modes or identifier format, the description is only minimally adequate for an agent to call this correctly on the first try.

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%, and the description does not explain the 'identifier' parameter beyond the schema's name and type. The agent must infer what kind of identifier is expected (DOI, URL, PMID, etc.). With zero coverage and no compensation in the description, this is a significant gap.

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 verb ('Fetch') and resource ('a legal open-access copy of a paper'), and clarifies that held papers cost nothing. It doesn't explicitly distinguish from siblings like 'search' or 'library', but the action is clear enough for an agent to understand the tool's core function.

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 when to use this tool: when you need a paper's full text and want to store it privately. It does not explicitly state when not to use it or name alternatives like 'search' for discovery or 'text' for extracting content. The context is clear but exclusions are absent.

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