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

With no annotations provided, the description carries the behavioral disclosure burden. It adds meaningful traits: the rule-2 filter, inclusive date boundaries, and the presence of a source filing_url on each record. It does not disclose ordering, pagination, or error behavior, but for a simple read-only date-range query these gaps are minor.

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 first states the tool's purpose and filter, the second clarifies an important property of the returned records. The main behavior is front-loaded and every sentence earns its place.

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 low-complexity tool with two required, fully documented parameters and no output schema, the description gives enough to invoke it correctly: the date range semantics are stated and the record content is partially described. It is not exhaustive about return fields or sibling routing, but it is complete enough for selection and basic use.

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 already describes both parameters as inclusive ISO YYYY-MM-DD dates, so schema coverage is 100%. The description's 'inclusive ISO date range' phrasing reinforces the schema but adds no new per-parameter semantics, matching the baseline for fully documented parameters.

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 identifies a specific resource ('Rule-2 insider-buy signals') and the core filter (filed within an inclusive ISO date range). It does not use an explicit action verb like 'returns' or 'lists', but the phrasing plus 'Each record carries...' makes the retrieval behavior clear and distinguishes it from ticker-based and single-day sibling tools.

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 the tool: when the agent needs Rule-2 insider-buy signals across a date range. However, it never explicitly contrasts this with sibling tools such as insider_signals_by_ticker or insider_signals_today, leaving the agent to infer the appropriate selection from the name and neighboring tool list.

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