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

Annotations already mark the tool as read-only and non-destructive, and the description adds meaningful behavioral context beyond that: what data is included (recorded ownership stages and assignment documents), a joint-owner interpretation caveat, and a legal non-opinion disclaimer. This gives the agent important information about output semantics that annotations alone do not convey.

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 front-loaded with the core behavior, followed by specific use cases, a sibling distinction, a joint-owner clarification, and a disclaimer. Every sentence earns its place; there is 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?

The tool has one parameter, a read-only annotation set, and no output schema, so the description carries most of the burden. It explains what data is returned, what questions the tool answers, how to interpret the data, and what it does not provide. Nothing essential is missing for an agent deciding whether and how to call 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?

The schema covers 100% of parameter documentation, including the serial number format and the explicit rejection of registration numbers. The tool description does not add parameter-level detail beyond that, but it does not need to given the schema's completeness.

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 identifies a specific action (trace ownership) on a specific resource (trademark ownership history over time) and clearly distinguishes itself from lookup_trademark, which only returns the current owner. The wording 'original applicant/registrant through each successive new owner' precisely defines scope.

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 explicit when-to-use guidance: ownership changes, assignments, transfers, chain-of-title, and due-diligence questions. It also names the alternative lookup_trademark and explains why that tool cannot answer these questions, plus includes a clear exclusion ('Not a title opinion').

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