Verify an insider-purchase claim against SEC Form 4

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

With no annotations, the description carries the full burden and does so thoroughly. It discloses the exact response statuses (confirmed, not_found, partial, out_of_scope, out_of_coverage), the coverage-window behavior, the itemisation of partial matches, and the 'no estimates' rule, giving the agent an accurate mental model of the tool's behavior.

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 action, then efficiently lists statuses and key rules without fluff. Every sentence earns its place: purpose, response variants, coverage-window guarantee, and the critical no-guessing policy.

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?

For a tool with 9 optional parameters and no output schema, the description unusually well explains what the tool returns and how it behaves across matching outcomes. It only marginally misses guidance on minimum required inputs (e.g., whether ticker/issuer or person alone suffices), but the schema and claim-components list make it largely complete.

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 each parameter meaning and format, and the description does not add substantive semantic detail beyond grouping them as 'ticker/issuer, person, amount, timeframe'. The mention of value/date matching tolerances is already present in the schema, so the description adds only limited value here.

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 opens with a specific verb and resource: 'Check a claim about an insider open-market buy ... against the filed record.' It clearly defines the tool's scope by naming the claim components and explicitly listing what is not covered (sales/options/grants), distinguishing it from the sibling signal and lookup 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?

The first sentence establishes the clear use case: verifying a factual claim against SEC Form 4, which differentiates it from the sibling discovery tools like insider_signals_by_ticker or insider_cluster_buys. It also states an exclusion ('sales/options/grants aren't covered') but does not explicitly name alternative tools for those cases, so it stops short of a 5.

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