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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description goes beyond them by disclosing that values appear only where the licence permits redistribution, that each row carries licence/attribution/evidence_url, and that publication_based_not_public is a factual status rather than a missing value.

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?

Purpose is front-loaded and every sentence carries information (licensing rule, row metadata, the not-a-missing-value clarification, the design-price scope). The parallel Japanese/English text is redundant for a monolingual reader but is a deliberate and consistent choice for this bilingual domain.

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?

An output schema exists, so row shape need not be explained, and the description still usefully names the licence/attribution/evidence_url fields. With 10 optional params and rich enum coverage in the schema, the description plus schema is sufficient for an agent to call this 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 the baseline is 3; the schema already documents all 10 params including geo, layer, status and period formats. The description adds value via the worked example and the cross-reference to get_jccdb_coverage for country-level layer availability, slightly exceeding baseline.

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 resource and scope: region, date and price status of an item in Japanese and U.S. public documents, plus the licensing condition on values. It carves out its niche against siblings by clarifying it returns public-works design unit prices rather than renovation estimates, though it never names the closest sibling tools (search_jccdb_items, get_jccdb_labor_rate).

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?

Gives a concrete calling example (query='生コンクリート', pref='奈良県') and a negative-scope warning (design unit prices, not renovation quotes), and points to get_jccdb_coverage for per-country availability. However, it never explicitly says when to choose this tool over sibling observation/price tools, leaving the routing to inference.

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