wb_reference

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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is clear. The description adds semantic context (e.g., LIC = low income) and the intent of the returned codes, which is beyond the annotations, but it does not detail return format or pagination—minor given the simple lookup nature.

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 sentences with active verbs and zero filler. The first sentence states the core purpose, and the second explains the downstream use case. Information is front-loaded and immediately usable.

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 tool with one enum parameter and no output schema, the description covers the purpose, the accepted values, and the practical application of the results. The agent has enough to decide when to call it and how to use the returned codes. Nothing critical is missing.

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 covers the enum parameter 100%, so the baseline is 3. The description adds meaning by enumerating the allowed values (regions, income levels, lending types) and by providing a concrete example of how the parameter value maps to a filter code used in wb_countries queries. This exceeds the schema's simple 'Which classification to list'.

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 states a specific verb and resource: 'Get World Bank classification lookup tables' and enumerates the three categories. It also gives a concrete example (LIC = low income) and connects to wb_countries-style filtering, which clearly separates it from sibling tools like wb_search/wb_indicator.

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 gives clear context for when to use this tool: to obtain classification codes for filtering wb_countries-style queries. It does not explicitly name alternative tools or state when not to use it, but the downstream use case is specific enough to guide selection.

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