get_index_stats

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

With no annotations provided, the description carries the transparency burden. It discloses that the tool returns statistics (e.g., indexed document count, company count, total characters), which implies a read-only operation. While it does not explicitly state side effects or access requirements, the nature of the tool is low-risk and adequately transparent.

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 a single concise sentence followed by a brief 'Returns' block. It is front-loaded with the action, contains no redundant information, and every sentence earns its place.

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 zero-parameter tool with an output schema, the description is complete. It provides an overview of the returned statistics (indexed document count, company count, total characters) and the output schema covers detailed field definitions. No further context is necessary for correct usage.

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 input schema has zero parameters, so the baseline for parameter semantics is 4. The description adds no parameter information (as none exist) and instead focuses on the return values, which is appropriate for a parameterless tool.

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 states the tool retrieves search index statistics using a specific verb ('取得します') and a distinct resource ('検索インデックスの統計情報'). It distinguishes itself from sibling tools like search_filings, list_indexed_companies, and compare_sections, which have different purposes.

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 implies usage for obtaining aggregate index statistics, but it does not explicitly state when to use this tool versus alternatives. There is no mention of such alternatives or situations where another tool would be more appropriate.

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