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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds valuable behavioral context beyond that: the data source is USPTO records, so coverage is limited to marks with USPTO records, and it is not a live query against WIPO/EUIPO. This prevents an agent from over-trusting the result or expecting real-time international 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 front-loaded with the core purpose, then lists the data fields, then the intended use case, then the data-source caveat. Every sentence adds distinct value and nothing is redundant with the schema or annotations.

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 single-required-parameter read-only tool with strong annotations, the description fully covers what an agent needs to know: what the tool does, what data it returns, when to use it, and its critical limitation regarding live WIPO/EUIPO data. No output schema exists, but the description enumerates the returned fields sufficiently.

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% and the only parameter, serial_number, is already described as 'USPTO serial number' in the schema. The description reinforces the context by saying 'by serial number,' but it does not add format, validation, or usage details beyond what the schema provides. Baseline 3 is appropriate.

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 opens with a specific verb and resource ('Get the international / foreign footprint of a U.S. trademark by serial number') and enumerates the exact data elements returned: IR number/date/status, 66(a) extensions, Madrid maintenance, and foreign priority filings. This level of specificity clearly differentiates it from sibling mark-related tools like get_mark_deadlines or get_mark_ai_summary.

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?

It gives an explicit invocation rule: 'Use this for ANY question about a mark's foreign, international, Madrid Protocol, WIPO, or EUIPO registrations.' It also states an important limitation — data is only from USPTO records and does not query live WIPO/EUIPO — which helps an agent avoid misusing it for live international data. It does not name alternative tools, but the guidance is clear enough.

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