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

Annotations already provide readOnlyHint=true, idempotentHint=true, and non-destructive, so the description does not need to repeat safety. It adds value by clarifying the tool is a lookup (inbound only) and that it returns metadata (coverage, provenance) rather than time-series data. This context helps set expectations beyond the annotations.

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 two sentences, front-loading the core purpose and output. It efficiently includes usage examples and exclusions. It is concise without being under-specified, although it could be slightly trimmed (e.g., 'available crossing measures, coverage' is dense but not wasteful).

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?

Given the simple lookup nature, no output schema, and 6 parameters fully documented in the schema, the description covers the tool's purpose, scope, and usage adequately. It doesn't specify response structure in detail, but that is less critical for a search tool, and the output fields are mentioned. It is complete enough for an agent to call 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?

The schema covers 100% of parameters with descriptions (e.g., limit, query, state, border, offset, response_format). The description mentions that query can be a port name, state, or exact code, but that info is already in the schema. It adds minimal nuance, such as the 'border' using official BTS labels, which is already in the enum. Baseline 3 for high coverage 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 explicitly states the action ('Search U.S. land-border ports'), the resource (LiveDataLink's BTS Border Crossing Entry snapshot), and the output (four-digit port codes, state, border, coordinates, crossing measures, coverage, pagination, provenance). It clearly distinguishes the tool from siblings like bts_transport_compare_ports or bts_transport_border_trend, which likely focus on analysis rather than lookup.

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 concrete example queries ('find the Laredo border port code', 'which Arizona ports have truck crossings?') and explicitly states when to use it (before a trend call) and what it is NOT for ('not wait times or outbound traffic'). Although it doesn't name specific sibling tools, the practical usage context is sufficient.

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