searchCompaniesByCIK

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

Annotations already declare readOnlyHint=true, openWorldHint=true, and idempotentHint=true, so the safety profile is covered. The description adds nothing beyond that: no indication of what fields are returned, whether filings are paged, or any coverage limits of the CIK lookup.

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?

Two sentences, but the second largely restates the first ("company details and filings linked to a specific CIK"). The marketing phrasing "Easily find" and the vendor API name consume space without adding actionable information.

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?

A single-parameter read tool is simple, but with no output schema the description is the only place to explain what the response contains, and it stays at the level of "essential company details and filings." Adequate to call, not adequate to predict the result.

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 sole parameter is fully documented in the schema (100% coverage), so the baseline is 3. The description only expands the acronym to "Central Index Key" and adds no format or type guidance (e.g., zero-padded string vs. integer) beyond the schema.

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 names a verb ("find") and a resource ("company information") keyed by a CIK, and repeats the API's marketing name. However, what actually comes back is vague ("essential company details and filings"), and it never distinguishes this tool from close siblings such as searchCIK, getCompanyProfileByCIK, or getFilingsByCIK.

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?

There is no guidance on when to use this versus the many sibling lookups (searchCIK, searchCompaniesByName, searchCompaniesBySymbol, getCompanySECProfile). The agent must infer the selection rule entirely from the name.

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