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

With only readOnlyHint=true from annotations, the description carries the burden and delivers: field-level return shape, newest-first ordering, limit default 50 / hard cap 200, is_activist defined as a form-type label rather than a judgement, and a FRESHNESS section explaining that keyless callers get stored rows and never trigger the EDGAR refresh (read stale/stale_basis). This is unusually rich behavioral disclosure.

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?

Dense but front-loaded, moving from purpose to return shape to caveats to freshness. Each sentence carries distinct information, though the run-on density is at the upper edge of what stays readable.

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?

No output schema exists, yet the description fully specifies the return object, row fields, ordering, pagination limits, a semantic caveat on reports_zero, and freshness behavior. An agent has everything needed to call and interpret it 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 both parameters are already documented, and the description's limit/default/cap details largely restate the schema. Baseline 3 is appropriate; the description adds no parameter meaning beyond what the schema provides.

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+resource (Schedule 13D/13G >5% beneficial-owner filings for a ticker) and explicitly distinguishes itself from 13F and from siblings like get_institutional_holders and get_institutional_consensus. An agent can identify exactly what this returns without opening the schema.

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 clear interpretive routing: cross-check get_institutional_holders before treating reports_zero as a sale, and notes it complements get_institutional_consensus. It frames usage well but does not state an explicit 'use this instead of X when...' selection rule.

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