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

Annotations already indicate readOnlyHint=true and openWorldHint=true, which the description does not contradict. The description adds return format ('one row per stock with cluster strength') but does not disclose additional behavioral traits like rate limits or data freshness. With annotations handling safety, the description provides moderate added value.

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 concise with two paragraphs: first explaining purpose and value, second listing parameters. It is front-loaded with the main idea. No redundant sentences, but could slightly tighten the marketing phrase to save space.

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 tool with three optional parameters and no output schema, the description covers purpose, parameter details, and return format. It does not cover error handling or edge cases, but given the simplicity and annotations (read-only, open-world), it is sufficiently complete.

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 schema has 0% description coverage, but the description fully explains all three parameters: ticker (optional filter), days_window (default 30, supported values 30/60/90), and min_insiders (default 3). This adds complete meaning beyond the raw schema, fully compensating for the lack of inline 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 uses a specific verb 'Detect' and clearly defines the resource: 'insider buying clusters'. It explains that it identifies multiple officers/directors buying the same stock within a window, which distinguishes it from siblings like 'get_form_4_insider_trades' that list individual 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 mentions it as a 'smart-money signal hedge funds pay $200+/mo for', implying premium value, but does not explicitly state when to use it versus alternatives like raw insider trade tools. It provides some implicit guidance by describing output, but lacks clear when-not or alternative tool references.

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