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

The annotations already declare readOnlyHint=true and openWorldHint=true, so the description does not need to re-state safety. It adds valuable context: the ordering ('newest first'), the window parameter, and the cost per call ($0.05). This goes beyond annotations and covers practical constraints, though it doesn't describe return format or pagination, keeping it at a 4.

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 two sentences: the first states the core function with specifics (filings, company, window, ordering), and the second provides the activist context and cost. Every word adds value, with no fluff or redundancy. It is front-loaded and highly efficient.

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?

With no output schema, the description does not explain the exact structure of returned filings, but it does convey the nature of the data (13D/13G filings) and the ordering. Given the tool's simplicity (3 params, clear purpose) and the strong annotations, the description is largely sufficient. A minor gap is the lack of mention of what fields are in the response, but it does not detract significantly.

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 descriptions for all three parameters are complete (100% coverage), so the description does not need to repeat them. It does add a little context by mentioning 'over a window' which aligns with the 'days' parameter, but no extra meaning beyond the schema is provided. The baseline of 3 is appropriate given the schema already carries the parameter semantics.

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 retrieves Schedule 13D and 13G beneficial-ownership filings for a specific company over a time window, sorted newest first. It explicitly names the regulatory filings (13D/13G) and the activist-position context, which distinguishes it from generic filing tools like latest_filings or recent_filings.

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 provides clear context: it is the first public signal of an activist position, implying use when seeking activist stake information. It mentions the cost per call, which is useful for decision-making. However, it does not explicitly state when NOT to use it or mention alternatives (e.g., using recent_filings for broader filing needs), so it falls slightly short of a 5.

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