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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful context beyond annotations: the data source (SEC EDGAR), the cost per call, and the returned fields. This is reasonable transparency for a read-only analytical tool.

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?

Three sentences, all informative: use case, return fields, source, and cost. It is front-loaded and contains no filler or repetition of schema details.

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 is sufficient to invoke the tool, but it does not explain the meaning or scale of cluster_score or activity signal, and there is no output schema to fill that gap. An agent receiving these values may not know how to interpret them. It also does not clarify whether days_back is required for meaningful results, though the schema marks it optional.

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. It mentions 'for a ticker' and 'over a window', which loosely maps to the ticker and days_back parameters, but it never names days_back or explains how the window relates to the parameter. The schema provides ranges, but the description adds minimal semantic value beyond what a caller can infer.

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 states a specific purpose: detecting insider trading clusters from Form 4 filing density over a window. It names the resource (Form 4 filings) and the output fields, making the tool's intent clear. However, it does not explicitly distinguish itself from sibling tools like get_sec_insider_trading or get_trader_signals.

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 'Use when detecting insider trading clusters from Form 4 filing density' gives a clear context for when to invoke this tool. It does not provide exclusions or compare to alternatives, but the use-case framing is actionable enough for an agent to select it.

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