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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuine value beyond these: the query-operator behavior with 'A ANDNOT B' and parentheses, the source attribution to the Kankoju portal, and a concrete enumeration of return contents (buyer, title, dates, URL, attachment links). No behavioral traits contradict the 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?

Three dense sentences with the core action front-loaded in sentence one, the source in sentence two, and filtering/return details in sentence three. Each sentence earns its place, though the final sentence is a long run-on listing capabilities and output fields in one breath.

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 10-parameter tool with no output schema, the description is substantively complete: it covers the data source, query syntax, all filter dimensions, and the return envelope. The only notable omission is explicit routing/contrast with the three tender-related siblings, but the core what-how-returns coverage is strong.

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 with the schema carrying the weight. The description restates filters (category, prefecture, procedure type, date range) and query operators that the schema already documents in detail, adding minimal new parameter meaning beyond framing the search as the entry point.

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 opens with a specific verb and resource: 'Search Japanese government tender notices (bid announcements) by keyword across national ministries, all 47 prefectures and municipalities.' This precise scope clearly differentiates it from siblings like japan_tenders_by_organization and japan_tenders_by_prefecture, which are structured around browsing rather than keyword search.

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 establishes a clear usage context: this is the keyword-driven search tool with optional filters. The emphasis on 'by keyword' and the coverage of all 47 prefectures implies when it should be chosen over the sibling organization/prefecture browsing tools, but it never explicitly names those alternatives or states when not to use them.

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