Today's insider-buy signals

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

With no annotations, the description carries the full burden. It discloses pagination via limit/offset, the total_matched count, and that each record has a filing_url. It does not mention rate limits or auth, but as a read-only query tool, the key behaviors are covered. The default of 25 and the limit<=0 no-cap behavior are also noted.

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?

Two sentences with no filler. The main purpose is stated first, followed by key behavioral details and parameter hints. Every clause adds information, and the structure is front-loaded.

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?

There is no output schema, so the description should clarify the response shape. It mentions total_matched and filing_url, giving some idea of the structure. However, it does not list all fields returned or describe error scenarios. Given the simplicity of the tool (4 optional params, no nesting), this is adequate.

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 coverage is 100% and each parameter already has a description. The tool description adds value by explaining how the parameters work together (e.g., default limit of 25, pagination with offset, and total_matched for full count). It also highlights the optional days/ticker filters, which helps an agent understand the intended usage context.

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 states the tool returns insider-buy signals that meet a specific rule (Rule-2, SEC code P open-market purchases) and are filed today by default. It explicitly names the resource and the action, and the detail about the default behavior (newest 25) distinguishes it from sibling tools like insider_signals_by_date_range or insider_signals_by_ticker.

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 usage for 'today' with optional days/ticker filters, but it does not explicitly compare to sibling tools or state when not to use it. The context is clear enough for an agent to infer that for arbitrary date ranges or specific tickers, other tools might be more appropriate, but this is not spelled out.

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