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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds valuable context: the range of indicators (20–60), the categories covered, and the data sources (World Bank WDI, IMF, UN, NASA POWER). It does not disclose any rate limits or pagination, but for a read-only, idempotent snapshot tool with an output schema, the description adds sufficient behavioral context without contradicting 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?

The description is three concise sentences. The first states the core action, the second lists the data categories and sources, and the third provides usage guidance and a use case. It is front-loaded with the purpose and contains no redundant information.

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 single-parameter tool with an output schema, the description is complete. It covers what the tool returns, the categories, the sources, the geographic scope, and a prerequisite for the parameter. The output schema handles return values, so no further explanation is needed. Nothing an agent needs to call it correctly 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?

Schema coverage is 100% with a detailed parameter description (format, length, examples). The description adds a meaningful hint by instructing to use country_code from africa.countries.list, which helps the agent source the correct value. This goes beyond the schema's format details and justifies a score above the baseline of 3.

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 uses a specific verb+resource: 'Get a live macroeconomic snapshot for an African country.' It clearly distinguishes from siblings like africa.data.indicator (which provides specific indicators) by focusing on a multi-category snapshot. It also mentions the scope (54 African nations) and lists the domains (economy, climate, health, demographics), 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 gives a clear use case ('ideal for rapid country assessment and investment screening') and a prerequisite ('Use country_code from africa.countries.list'). It does not explicitly contrast with alternatives like africa.data.indicator, but the context strongly implies that for a broad snapshot this tool is preferred, while for a specific indicator another tool would be used. The guidance is present but lacks an explicit when-not-to-use statement.

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