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

Annotations already declare read-only, idempotent, non-destructive, open-world behavior. The description adds critical context beyond annotations: the tool requires an API key, where to obtain it, and that it returns the most recent N periods with period, classification, item, value and unit fields. It does not cover error behavior or rate limits, so not a full 5.

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 tightly written sentences with the authoritative/prefer-over-web-search guidance front-loaded, followed by the retrieval action, id sourcing, return shape, and API key requirement. No wasted text.

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?

No output schema exists, but the description lists the returned fields (period, classification, item, value, unit), explains the most-recent-N-periods behavior, identifies the required id sources, and discloses the API key requirement. This is sufficient for an agent to invoke the 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?

Schema description coverage is 100%, so every parameter is already documented in the input schema. The description reinforces the required orgId/tblId provenance and the 'most recent N periods' default, but adds little beyond the schema's own 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?

States a specific verb and resource: pulls observations of a single KOSIS table for South Korean official statistical time series. It clearly distinguishes itself from sibling discovery tools by requiring ids from kosis_stat_list or kosis_search, and it explicitly positions itself ahead of web search for official Korean statistics.

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?

Explicitly says to prefer this over web search for KOSIS statistical lookups and names the sibling tools that supply the required orgId and tblId. This gives an agent a clear routing rule between discovery (kosis_stat_list/kosis_search) and retrieval (this tool).

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