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

With no annotations, the description carries the full burden and handles it well: no arguments, no filtering, fixed cap, ordering, and data-freshness semantics ('a Form 4 is filed within two business days of its transaction'). It also discloses the pricing pointer, which is useful context beyond the schema.

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 every sentence earns its place: scope, ordering, cap, no-args rationale, sibling routing, filing-latency context, and pricing. It is front-loaded with the core behavior and contains no filler.

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 zero-argument tool with no annotations and no output schema, the description covers what it does, why it exists, when to use alternatives, the response cap, and freshness semantics. An agent has enough to select and invoke it correctly without further context.

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 documents zero parameters, and the description reinforces that this is deliberate: 'no filter, no paging, no way to ask for more'. For a 0-parameter tool, this exceeds the baseline by explaining why the absence of arguments is intentional.

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 states exactly what the tool returns: 'most recently filed Form 3, 4 and 5 rows in the corpus... newest filing first, capped'. It also explicitly distinguishes itself from filtered sibling tools by saying 'Every filter is on another tool' and naming them.

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 explains that the tool has 'no filter, no paging, no way to ask for more', establishing it as a quick live-corpus probe rather than a query tool. It explicitly routes filtered needs to alternatives like issuer_insider_activity and screen_insider_transactions, giving clear when-to-use and when-not-to-use guidance.

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