Search Japanese filings (EDINET)

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

Annotations already cover readOnlyHint and openWorldHint, but the description adds substantial behavioral context beyond them: there is no search-by-company endpoint, the scan walks back one day at a time, each day costs a request, and there is a strong seasonal clustering of annual reports in late June. This is exactly the kind of cost/timing disclosure the annotations cannot express.

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?

Front-loaded with purpose and routing, then the operational caveats. Every sentence carries real information, though the late-June fiscal-year point is effectively stated twice (in the body and again as 'Set startDate to late June'), a minor redundancy for an otherwise efficient definition.

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?

With no output schema, the description still tells the agent what comes back (document ids) and where they go. All four parameters are documented, and the date-indexing behavior and caching are disclosed. Nothing an agent needs to call this 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%, so the baseline is 3, but the description meaningfully augments two parameters beyond their schema text — it explains the cost rationale for maxDays ('each day is a request') and tells the agent what value startDate should actually take (late June). It does not explain annualOnly or query beyond the schema, hence not a 5.

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 (Find) and resource (Japanese regulatory filings / EDINET), names the accepted identifiers (company name, TSE ticker, EDINET code), and explicitly distinguishes itself from the companion tool by saying it 'Returns document ids to pass to `edinet_financials`.' An agent can separate search from retrieval without opening either schema.

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?

Explains when the tool will and won't work: EDINET is indexed by date not company, searching a November window will usually find nothing, and startDate should be set to late June for annual reports. It also routes the agent onward to edinet_financials. This is explicit when-to-use and when-not-to-use guidance.

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