search_unpaywall

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

With no annotations provided, the description carries full burden and does well. It discloses key behavioral traits: extracts first DOI from query, returns at most one record, returns empty list for unresolvable DOIs, and mentions API consistency for max_results. It doesn't cover rate limits or authentication needs, but provides substantial operational context.

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?

Perfectly structured with clear sections: purpose statement, important constraint, behavioral details, and parameter explanations. Every sentence earns its place with zero waste. The information is front-loaded with the most critical constraint (DOI-centric nature) stated immediately.

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 2 parameters with 0% schema coverage and no annotations, the description provides complete operational context. It explains what the tool does, its limitations, how parameters work, and return behavior. With an output schema presumably covering return format, the description focuses appropriately on usage constraints and parameter semantics.

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 description must compensate fully. It provides excellent parameter semantics: explains that 'query' can be DOI string or text containing DOI, clarifies that 'max_results' is kept for API consistency but Unpaywall returns max 1 record. This adds crucial 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 specific action ('lookup a DOI via Unpaywall'), resource ('OA metadata'), and scope ('DOI-centric, does not support generic keyword search'). It distinguishes from sibling tools by explicitly mentioning Unpaywall's DOI-centric nature, unlike many other search/download tools in the list.

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?

Explicitly states when to use ('lookup a DOI') and when not to use ('does not support generic keyword search'). It provides clear alternatives by implication - for generic searches, use other sibling tools like search_arxiv, search_crossref, etc. The guidance is specific and actionable.

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