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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), but the description adds genuinely useful context: the data is Kabuken-derived rather than raw FSA filings, and the source/licensing is disclosed. The derived-data caveat is a real behavioral trait an agent would not otherwise know. It stops short of noting rate limits or response size.

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 lead sentence is well front-loaded and the return shape is stated early, but the provenance block is repetitive: 'processed by Kabuken, not raw unprocessed FSA data' is immediately restated as 'calculated by Kabuken from EDINET filings, not reported directly by EDINET.' Full license URLs consume space without aiding tool selection.

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 one-parameter read tool with no output schema, the description covers purpose, output shape, provenance and licensing adequately. The remaining gap is operational: nothing tells the agent where industry_id values come from.

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 description coverage is 100% and the single industry_id parameter is documented with an example and the note that a bare code is accepted. The description adds nothing beyond the schema, which is the expected baseline for full coverage.

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, resource and scope: aggregated financial ratio statistics for all companies in a Japanese industry classification. It also spells out the shape of the result (mean, median, count plus top/bottom 3 per ratio). It does not explicitly contrast itself with siblings like compare_companies or screen_companies, so it is clear but not sibling-differentiating.

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?

Usage is implied by the scope statement, but there is no explicit 'use this when' condition and no mention of list_industries as the way to obtain a valid industry_id. The agent must infer both the selection case and the prerequisite step.

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