wb_topics

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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds behavioral context beyond these: it explains that omitting topic_id yields a list of all 21 topics, while providing topic_id yields indicators under that topic. This dual-mode behavior is not inferable from the schema alone and is valuable for the agent. It does not mention pagination, return format, or error handling, but given the simplicity and annotation coverage, this is acceptable.

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?

Two concise sentences with no redundant wording. The first sentence immediately states the purpose, and the second explains the two modes with concrete examples. All information is front-loaded and every word earns its place. No filler or unnecessary elaboration.

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 tool's simplicity (one optional parameter, no output schema), the description is complete. It explains what the tool returns in both modes ('lists all 21 topics' and 'lists every indicator under that topic'), provides example topics, and frames its usage. The annotations cover safety and idempotency. There is no missing information that would prevent an agent from calling this tool correctly.

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?

The schema description already explains the topic_id parameter with an example ('8' = Health) and says to omit it to list all topics. The tool description reinforces this by explaining the two modes and listing example topics (Agriculture, Health, Climate Change, Education). This adds practical context about valid values and the parameter's presence/absence semantics, going slightly beyond the schema. Since schema coverage is 100%, the description adds value by clarifying behavior but not entirely necessary, hence a 4.

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's function: 'Browse World Bank indicators by theme.' It specifies two behaviors based on the optional topic_id parameter, listing all topics or indicators under a topic. This distinguishes it from related siblings like wb_search (which implies keyword-based discovery) and wb_indicator (which likely retrieves specific indicators). The phrase 'without keyword guessing' directly contrasts with search-oriented tools, making the purpose unambiguous.

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 clear context on when to use the tool: to discover indicators by theme, especially when the user doesn't know exact keywords. It explicitly describes the two modes (with and without topic_id) and frames it as 'the best way to discover indicators for a subject.' However, it does not explicitly name alternative tools (e.g., wb_search) for cases where a keyword is known, though it strongly implies this. Slightly more explicit guidance would warrant a 5.

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