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

Annotations already mark the tool as read-only and idempotent, and the description adds non-obvious behavioral details: the 90-day insider lookback, latest complete versus in-progress quarters, and the reason share classes are treated as separate tickers. This is valuable context beyond the annotations, with no contradiction.

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 dense but organized by data category, with the core purpose front-loaded. It is longer than the minimum, but each clause carries meaningful distinguishing information, so the length is justified.

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 covers the tool's scope, data definitions, edge cases like share classes and in-progress quarters, and explicitly routes to sibling tools for more detailed lists. With an output schema present and read-only annotations, an agent has everything needed to invoke this tool correctly.

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 the single ticker parameter is already well-described with examples and dot-notation handling. The description reinforces that share classes are separate tickers and that the stock must be US-listed, but it adds little beyond what the schema already provides.

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 opens with 'Overview of one US-listed stock' and enumerates the exact data sections returned: company facts, insider activity, 13F ownership, and superinvestor holdings. It also distinguishes itself from sibling full-list tools by explicitly naming get_insider_trades and get_stock_13f_holders.

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 sets clear scope ('US-listed stock', one ticker) and provides explicit routing guidance: 'Use get_insider_trades and get_stock_13f_holders for the full lists.' The quarter-completeness note also sets expectations about data freshness, which helps an agent decide whether this overview is sufficient.

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