cluster_buys

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds meaningful behavioral context: the exact definition of a cluster buy, the filing code involved, the market-wide scope, and that results are sorted by total dollars. This goes beyond the structured annotations without contradicting them.

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 well-organized: a one-sentence summary, a precise definition, market universe and sort order, then an Arg list. It is slightly wordier than necessary—'one of the stronger public signals' is more promotional than operational—but every sentence contributes useful context and the parameter section is clean.

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 read-only query tool with three optional parameters and an output schema, this description is complete. It defines the domain, explains the signal semantics, specifies the sort order, and documents all parameters with ranges and defaults. The output schema covers return values, so no further return-shape detail is needed.

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 0%, so the description must compensate for the undocumented parameters. It does so fully by explaining each parameter's purpose, allowed range, and default: days as look-back window, min_buyers as minimum distinct insiders, and limit as rows to return. This gives the agent everything needed to set meaningful values.

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 tool's output: companies with cluster buys by corporate insiders. It gives a specific definition (two or more distinct officers, directors, or 10% owners filing Form 4 code P) and distinguishes itself from Congress-only trading by saying it is market-wide. It does not use an explicit verb like 'returns' or 'lists,' and it doesn't name a sibling tool, but the resource and scope are unambiguous.

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 implies when to use this tool: when you want open-market insider cluster-buy signals across all companies. It also explicitly says it is 'not limited to what Congress trades,' which hints at a distinction from congress_trades. However, it does not explicitly state when to use this vs. a specific alternative, nor does it mention any exclusions or complementary tools.

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