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

With no annotations, the description carries the full behavioral disclosure burden. It explains the filtering rule and notes each record includes the source filing_url, which is useful. However, it does not clarify the meaning of 'in-window,' result ordering, limits, or other behavioral traits an agent might need.

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, well-structured sentence that front-loads the core definition and includes only essential details. Every clause adds meaning, and there is no redundant or filler content.

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 zero-parameter read-only tool, the description adequately explains what the tool returns and highlights an important record field. It is slightly incomplete in defining 'in-window' and how this relates to sibling signal tools, but the low complexity keeps the gap small.

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?

The input schema has zero parameters, so the baseline is 4. The description's mention of filing_url is not parameter-related but adds useful output context; no parameter documentation is needed 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 clearly identifies the resource as the Rule-2 cluster-buy signal subset with a concrete definition (>=2 insiders buying the same issuer in-window). It distinguishes itself from sibling signal tools by calling it the 'highest-signal subset,' though it lacks an explicit verb like 'list' or 'return.'

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 phrase 'highest-signal subset' implies this tool is for users seeking top-signal cluster-buy activity, but it does not explicitly state when to use this over sibling tools or when not to use it. No alternatives are named, so the routing guidance is mostly implicit.

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