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

The description goes well beyond the annotations: it discloses possible overwrite of existing records under D1 settings, explains that absence from documents does not imply no capital relationship (aligned with openWorldHint), and flags internal fields such as relationId as not user-facing. None of this contradicts the annotations; it enriches them meaningfully.

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 carries a distinct fact: core action, overwrite side effect, non-inference limitation, open-world caveat, output presentation, and downstream workflow. The most important information is front-loaded, and there is no redundant filler.

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 destructive, open-world tool with no output schema and six parameters, the description covers critical side effects, result interpretation, internal-vs-user-facing output, and the correct next step. The only minor gap is that it never states the exact return shape (e.g., confirmed/not-confirmed structure), though it references internal fields that will appear, so an agent can still act reasonably.

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?

All six input parameters already have individual descriptions in the schema, and schema coverage is 100%, so the baseline is 3. The description adds useful high-level behavioral context, but it does not add parameter-specific meaning beyond what the schema already provides. There is no need for the description to compensate here.

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: verifying a user-declared parent-company candidate against the latest EDINET securities reports. It also explicitly scopes itself negatively ('not a tool for inferring a parent from zero'), which differentiates it from search/company-profile siblings. This makes the tool's unique role very clear.

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 clearly states when to use the tool: when a user has declared a parent candidate to be verified, and it explicitly warns against using it for guessing from scratch. It also gives downstream guidance to check program guidelines and use assess_deemed_large_enterprise_eligibility. However, it does not name a direct alternative for the same verification-style task among siblings, so it is not a perfect 5.

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