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

Beyond readOnlyHint=true, it discloses the token cost (10), the 93-day maximum window, the download route /stable/filing-document with no age limit, and a redistribution restriction — real behavioral context an agent cannot get from annotations. It omits pagination behavior and how the limit parameter affects result completeness.

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?

Key facts are front-loaded, but the entire content is duplicated verbatim in Japanese, and the timezone/format rule appears twice within the English text, roughly doubling length without adding information. An agent reading one language gets everything, so the second pass is pure overhead.

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 read-only listing tool with no output schema, it covers cost, date-window limits, timezone conventions, and how to fetch the actual PDF — everything needed to call it correctly. The only gap is the undeclared limit default/ceiling semantics (100/500) and whether results are paginated.

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?

Adds meaning beyond the schema by clarifying that from/to are JST calendar dates while returned date-times are UTC ISO 8601 (+9h for JST) and that symbol omission requires from/to — the latter is echoed in the schema, but the timezone rule is new. The limit parameter's purpose remains undocumented in both schema and description.

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?

Opens with a specific verb+resource ('TDnet timely-disclosure document list') and enumerates the returned fields (announcement time, title, document-type code, pdfUrl). It is clearly distinguishable from the many financial-statement and profile siblings in the get_* family.

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 states the two filtering modes: by company (symbol) or by date window across the whole market, and adds the precondition that omitting symbol makes from/to mandatory. It does not name a sibling alternative for overlapping disclosure/news needs, but the when-to-use context is unambiguous.

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