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

The description adds substantial behavioral detail beyond the annotations: shares come only from the most recent Form 3/4/5 filing, options and derivatives are excluded, figures are restated onto today's split basis, Indirect can understate because only the last vehicle balance is kept, and former insiders may show stale dates or zero shares. These nuances materially affect how an agent interprets results.

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 efficient: it front-loads the core purpose, then packs several important caveats into compact sentences, ending with clear usage guidance. Every sentence contributes meaningful information about behavior or usage, with no filler or tautology.

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 no output schema, the description carries the responsibility of explaining what the result contains, and it does so thoroughly: source filings, ownership buckets, split adjustment, exclusions, indirect holding limitations, max results, and ranking order. An agent has enough context to call the tool and correctly interpret the response.

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 all three parameters. The description adds useful contextual semantics like the maxResults default and implicit ranking by total shares, but it does not significantly extend the meaning of individual parameters beyond what the schema provides. Baseline 3 is appropriate.

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 the exact verb and resource ('Get a summary of insider ownership for a stock'), specifies the ranking basis ('ranked by total shares held'), and clearly differentiates itself from sibling tools like GetInsiderTransactions and GetInsiderSentimentScores. It is unambiguous about what the tool returns.

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 explicitly states when to use this tool ('Use this to understand the insider ownership structure of a company') and names the alternative for the underlying trades ('use GetInsiderTransactions'). This gives an agent clear routing guidance without needing to infer usage from the schema.

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