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

With no annotations, the description carries the full behavioral burden and does so well: it discloses the default amendment behavior, result cap, EDGAR history depth, data source, no-API-key access, error non-charging, and the $0.002 USDC x402 cost per call.

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 purpose and returned fields, and every sentence adds relevant information. It is dense and somewhat run-on, but there is little wasted wording.

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?

Although there is no output schema, the description enumerates the returned fields and covers filtering, limits, history scope, data source, cost, and error charging. That is enough for an agent to understand and call 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?

Schema coverage is 100%, so the schema already documents all six parameters. The description adds useful examples for forms and clarifies the amendment default, but it does not add much beyond the schema and omits company identifier formats that are present in 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 states a specific verb and resource: list a company's SEC filings, newest first, with a detailed set of returned fields. It is clearly distinct in substance from company facts or filing text, but it does not explicitly name or route against the sibling tools.

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 clear listing purpose and by the filter options for form types and date range. However, there is no explicit guidance on when to use this versus company_facts, company_lookup, or filing_text, and no when-not guidance.

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