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

The description adds substantial behavioral context beyond the readOnlyHint annotation: results are returned 'largest first,' the default txn_code 'P' means open-market purchases, and the description warns that including grants, withheld shares, and option exercises as buying is a common error. It also explains the data volume ('about 103,000 a quarter'), which signals potential cost/performance characteristics.

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 a one-sentence functional summary, then uses the remaining sentences to add differentiation, parameter semantics, and a statistically grounded warning about the default txn_code. The additional context about Form 4 composition and the 103,000-filing volume earns its place by preventing a common analytical mistake.

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?

The description provides enough orientation for an agent to select and invoke the tool for market-wide insider transaction queries, and the presence of an output schema covers return-value details. The only notable gaps are the exact format for start/end and explicit semantics for limit, but the default values and overall framing make this a mostly complete definition.

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?

With 0% schema description coverage, the description compensates for txn_code and min_value, explicitly listing codes and stating that 'min_value bounds the dollar size.' It also refers to start/end as a 'date window,' but it does not specify the expected date format. The limit parameter is not explained in the description, leaving a gap for a tool with five parameters and no schema-level descriptions.

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 precise statement of scope: 'Every insider transaction of one type across ALL issuers in a date window, largest first.' It names the resource, the aggregation axis, the filtering by transaction type, and the sort order. It also distinguishes itself from the per-company insider feed, so an agent can differentiate it from sibling get_insider_trades.

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 frames this as 'the issuer-axis inverse of the per-company insider feed' and explains that no other endpoint serves this market-wide aggregation. It also emphasizes that the txn_code default of 'P' is central to correct usage. It stops short of explicitly saying 'use get_insider_trades when you need a single issuer,' but the guidance is clear.

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