get_equities_master

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

Annotations already declare readOnly, idempotent, and non-destructive behavior. The description adds useful behavioral details: no-parameter invocation returns all listed stocks for today, 4-digit codes match ordinary shares only, and accepted date formats. It does not mention pagination or rate limits, but it goes beyond the annotation baseline.

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 front-loaded with the core definition, followed by short use-case, default behavior, supported plan, and argument lines. Every line adds information without unnecessary prose, making it appropriately sized and well-structured.

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?

The tool is simple with two optional string parameters, a read-only operation, and an output schema present. The description covers purpose, parameters, default behavior, and supported plans, which is sufficient for an agent to select and invoke the tool 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?

The schema provides only defaulted nullable string properties with no descriptions, and schema coverage is 0%. The description fully compensates by explaining the 5-digit code format with an example, the 4-digit ordinary-share behavior, and the accepted date formats (YYYYMMDD or YYYY-MM-DD).

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 clearly identifies the tool as a listed stock master ('上場銘柄マスタ') returning company name, industry code, and market segment, and lists concrete use cases such as ticker lookup and sector code lookup. This distinguishes it from sibling tools by emphasizing static master data rather than bars, search, or derivatives.

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?

It provides explicit 'Use for' scenarios (銘柄名, 会社名, 業種, 市場区分, ticker lookup) and states the default behavior when parameters are omitted. It does not name alternative tools or when-not-to-use conditions, so it stops short of a full 5, but the usage context is clear.

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