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

Annotations already cover the safety profile (readOnly, idempotent, openWorld, non-destructive), so the description correctly spends its budget on non-obvious behavior: the `structured: true/false` row flag tied to SEC's 2024 XML rule and the auto-resolution of ticker/name to CIK. It stops short of mentioning pagination/ordering behavior, but the added data-coverage context is genuinely useful.

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?

Front-loaded with purpose and scope, then the input resolution, then the structured-flag caveat, then the handoff to sec_13d_filing. Every sentence carries information, though the quoted example phrases and emphasis add some visual noise without adding semantics.

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?

With an output schema present, the description needn't explain return shape, and it covers everything else an agent needs: what it lists, accepted identifier forms, the filter families, the structured-vs-text data caveat, and the downstream tool for owner detail. Complete for this complexity level.

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%, so the schema already documents aliases, the enum filter semantics, and the limit range. The description adds only the auto-resolution-to-CIK note, which is marginal over the schema; baseline 3 is appropriate when the schema does the heavy lifting.

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?

States a specific verb and resource ('List Schedule 13D / 13G beneficial-ownership filings... for one issuer') and explicitly positions itself as the AUTHORITATIVE source for the 'who owns 5%+' question. It also distinguishes itself from the sibling sec_13d_filing by framing this tool as the listing step and that one as the detail step.

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?

Gives explicit when-to-use framing ('who owns 5%+', 'has an activist filed a 13D') and an explicit handoff rule: 'Use sec_13d_filing on any accession_number returned here to get the actual reporting-owner data.' The listing-vs-detail division of labor with the sibling is unambiguous.

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