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

With no annotations, the description carries the full burden and covers key behavior: it discloses the observed_at and happened_at fields, explains the exclusion rationale, and details the 13D/13G inclusion with direction semantics. It does not mention output format or pagination, but the essential behavior is transparent.

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 a single dense paragraph, but each sentence adds distinct value: purpose, exclusions, data fields, alternative tool, and the 13D/13G extension. It is front-loaded with the core definition and remains readable despite its length.

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?

Given four parameters and no output schema, the description covers the essential: what data is returned, what is excluded, how to filter, and the alternative tool. It could mention pagination or default date range, but the core context is complete for selecting and invoking the tool.

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 75%, so the schema already documents most parameters. The description adds meaning to form by explaining 13D vs 13G and direction=buy on initial filing, and notes min_value only applies to Form 4 rows. It does not add to since/ticker but they are self-explanatory.

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 clearly defines the tool as listing SEC Form 4 open-market insider buys, with explicit exclusion of compensation events (grants, options, etc.). It distinguishes itself from insider_sells by naming it as the alternative for disposals, making the purpose unmistakable.

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?

It explicitly says 'For disposals use insider_sells', providing a direct when-not-to-use instruction. It also explains the form parameter for filtering 13D/13G and notes that form=4 restricts to Form 4 only, giving clear context for selection.

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