search_unpaywall

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

With no annotations, the description fully governs behavioral disclosure. It states the tool extracts the first DOI from query, returns at most one record, and returns an empty list if not resolvable. This covers the key behaviors and error handling without needing annotations.

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 description is concise: four short sentences covering purpose, usage, parameters, and return. Front-loaded with the verb 'lookup' and resource 'Unpaywall', every sentence earns its place without redundancy.

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?

Given the low complexity (2 params, no enums) and presence of an output schema, the description is complete. It covers purpose, usage constraints, parameter roles, and return behavior. No gaps remain for effective tool selection.

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 0%, so the description compensates fully. It explains 'query' as a DOI string or text containing a DOI, and 'max_results' as a placeholder for API consistency, adding significant meaning beyond the bare schema.

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 clearly states the tool looks up a DOI via Unpaywall and returns OA metadata. It explicitly distinguishes from generic keyword searches, aligning with its name 'search_unpaywall' and the sibling search tools that support keyword queries.

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 provides explicit when-to-use (DOI lookup) and when-not-to-use (not for keyword search). It also clarifies that Unpaywall returns at most one record, so max_results is merely for API consistency, guiding the agent to expect a single result.

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