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

With no annotations, the description carries the burden and does so well: it discloses the data source, the code-S filter, the observed_at vs happened_at distinction, the 13D/13G direction computation, and the min_value caveat. It stops short of describing output ordering or pagination, but those are minor for a read-only SEC data tool.

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?

Every sentence earns its place: purpose, filtering rule, interpretive caveat, key date fields, sibling routing, and secondary 13D/13G behavior are packed without filler. The most important scope statement 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?

For a tool with no output schema and no annotations, the description is thorough about input semantics and result fields. It leaves out explicit output structure/pagination, but the agent has enough to select and call it correctly with optional filters.

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 already covers 75% of parameters, and the description adds real semantics: form values map to filing types, min_value only applies to Form 4 rows, and 13D/13G direction is relative to the last filing seen. Ticker remains undocumented in both schema and description, which is the only gap.

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?

States the exact scope: SEC Form 4 open-market insider sells (code S only), plus Schedule 13D/13G stake decreases and sub-5% exits. This clearly differentiates the tool from insider_buys and from generic trade lists.

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?

Explicitly routes acquisitions to insider_buys, warns that sells carry less signal than buys, and explains how to restrict to Form 4 with form=4. The agent knows when and when not to invoke this tool.

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