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

Annotations already establish a read-only, idempotent, non-destructive profile. The description adds useful context by naming the result fields returned (title, authors, date, type, MeSH subjects, abstract, permanent link) and the scope of sources. No contradiction with 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?

Three sentences with no filler: action and scope first, return-value content second, usage guidance last. The detail about document types and result fields 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?

For a search tool with 3 well-documented parameters and no output schema, the description is complete enough: it defines what is searched, what each result contains, and when to use the tool. No essential operational gap remains.

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 query, page, and limit. The description repeats some query semantics but adds no material constraints or format details beyond the parameter descriptions.

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?

Begins with a specific verb and resource — 'Search WHO publications and official documents' — and enumerates document categories and search dimensions. This makes it easy to distinguish from siblings like who_iris_item, which is presumably item retrieval rather than search.

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 explicit guidance: 'Use to find what the World Health Organization has actually published on a health topic.' It does not list exclusions or alternative tools, but the intended use case is clear and unlikely to be confused with unrelated siblings.

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