fetch_article

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

No annotations are provided, so the description carries full burden. It discloses the return values (title, abstract with section labels, authors, journal, etc.) and the error case (NOT_FOUND for invalid PMID). Missing any mention of side effects or limitations, but for a read-only fetch, this is sufficient.

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 extremely concise: two sentences. The first sentence states the core purpose, and the second enumerates output and error handling. No extraneous words, optimally front-loaded.

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 simplicity (1 required parameter, output schema exists), the description covers the essential aspects: what it does, what it returns, and error handling. It could mention input format expectations more explicitly, but the example in schema suffices.

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% with a clear description and example for the 'pmid' parameter. The main description adds no further semantics beyond stating the tool's purpose. Baseline score is appropriate as the schema already documents the parameter well.

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 'Fetch one article with full abstract text', specifying the verb 'fetch' and the resource 'one article'. It lists the output fields, distinguishing it from sibling tools that search or find related articles. This is specific and actionable.

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 usage when a PMID is available through the required parameter, but does not explicitly state when to use this tool versus alternatives like search_pubmed or find_related. No guidance on when not to use or for broader queries.

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