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

Annotations already declare readOnlyHint and destructiveHint, so the bar is lower. The description adds value by detailing the returned fields (owner, status, filing dates, goods/services, correspondent) and highlights the correspondent usage, which is beyond what annotations provide. It does not disclose edge-case behavior (e.g., not-found handling), but this is minor for a read-only lookup.

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, front-loaded sentence that lists key returned data and a specific use case. There is no redundancy or filler; each clause earns its place, and the 'use this for' parenthetical is directly actionable.

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 is simple (one parameter) and has an output schema, so the description does not need to explain return values. It covers the core purpose, key data fields, and a prominent use case. Given the low complexity and rich schema/annotations, the description is complete enough for an agent to select and invoke the tool correctly.

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%: the description's wording 'by its serial number' aligns exactly with the parameter schema, which already explains the format and constraints. The description adds no new semantic information about the parameter, so the baseline score of 3 applies.

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 'Get detailed information about a specific USPTO trademark by its serial number,' which is a specific verb-resource pair. It distinguishes itself from siblings by listing the types of information returned (owner, status, filing dates, goods/services, correspondent) and the targeted use case for correspondent questions.

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 explicit guidance for when to use the tool, specifically for 'which firm represents/is correspondent for' questions. However, it does not mention exclusions or explicitly name alternative tools for other scenarios, so it lacks the 'when-not-to-use' clarity of a fully scored guideline.

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