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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint false, covering the safety profile. The description adds valuable behavioral context by stating that 8-K item codes are decoded into readable event types (earnings release, acquisition, etc.), which goes beyond the annotations. It does not contradict the annotations and adds meaningful insight into what the tool does with the data.

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 a single, information-dense sentence that front-loads the core purpose (SEC Form 8-K filings) and efficiently conveys the decoding behavior and the question it answers. There is no wasted wording, and it is easy to parse.

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 is complete for a read-only tool with an output schema. It states the domain (US-listed companies), the specific filing type (8-K), the value-add (decoded item codes), and the answer it provides (what events and when). No essential information is missing for an agent to decide whether to invoke it.

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%, so the baseline is 3. The description does not add additional detail about parameters beyond what the schema provides; it implies the purpose but does not explain parameter syntax or format. It meets the baseline without extra compensation.

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 a specific verb and resource: it answers what significant corporate events a company has disclosed via SEC Form 8-K filings, and decodes item codes. It is not a tautology and distinguishes itself from sibling tools like insider_13d, insider_trades, and insider_activity_summary by focusing on 8-K material events.

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 gives clear context about when to use it (when needing 8-K material events), but does not explicitly name alternatives or state when not to use it. The sibling names imply the distinction, but the description itself does not provide explicit routing guidance. This is clear context without exclusions.

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