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

Beyond annotations that already mark it read-only, idempotent, and non-destructive, the description adds meaningful behavioral context: the typical payload size (612 KB), the impossibility of filtering, the data distribution around secCode, and the downstream use of docID. This helps an agent anticipate cost and output shape before calling.

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?

The description is dense but every sentence earns its place: it states the core action, explains both response modes, warns about payload size, notes data characteristics, and links to the next logical tool. The most important scoping information is front-loaded.

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 two-parameter, read-only API with an output schema, the description covers everything needed to call it correctly: required date, type differences, return locations, size/performance caveat, absence of filters, and onward data flow. Nothing an agent needs is left to guesswork.

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%, but the description goes well beyond the schema by explaining exactly what each type value returns, where the count lives in type=1, and which fields appear per filing in type=2. It also reinforces the required date format, making parameter choice unambiguous.

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: 'Lists every disclosure filed with Japan's EDINET on one date.' It also clarifies the lack of filters, which differentiates it from any filtered disclosure tool and explicitly connects docID to the downstream download tool.

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 clear operational guidance: date is required, type=1 gives count and metadata, type=2 returns the full filing list, and users should check the count first when in doubt. It does not explicitly name alternatives among siblings like edinet_filings_digest, so it falls short of full when-not/alternative guidance.

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