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

With no annotations, the description carries the full behavioral burden, and it only discloses the metric categories in the result. It is silent on whether the call is read-only, whether it returns all municipalities in a prefecture or a single municipality, whether values are per-year or per-capita, and what the response shape looks like.

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?

One short parenthetical phrase — there is no wasted wording, but the terseness is under-specification rather than economy. The metric list is front-loaded and useful; everything else an agent needs is absent.

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 one-parameter read tool, the description is complete enough that an agent knows it is a census lookup by municipality. But with zero annotation coverage, no output schema and an undocumented parameter, the description leaves key call-shaping details unresolved.

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 0% for the single required parameter 'prefecture', so the description must explain it, and it does not mention the parameter at all. The phrase '市区町村別' only hints at municipal granularity without clarifying whether the prefecture value filters, expands, or is required.

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 Japanese phrase names the resource ('市区町村別センサス', municipality-level census) and lists the metrics returned (population, corporation counts, POI counts), so an agent can infer it retrieves municipal statistics. However, there is no verb and nothing that separates it from adjacent siblings such as jp_density, jp_catchment or jp_quality, which plausibly cover overlapping geographic data.

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 no when-to-use guidance whatsoever: no indication of when this census beats jp_density or jp_catchment, no preconditions, no mention that data is scoped to Japan or to a single prefecture. Usage must be guessed entirely from the name.

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