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

With no annotations, the description carries the full burden and does well: it discloses update frequency ('Updated every 30 minutes from US Customs and Border Protection') and return fields (delay minutes, lanes open, port status). It does not explicitly state read-only behavior or limitations, but the nature of the tool makes it clear.

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 concise and well-structured, with four sentences each adding value: purpose, return data, update frequency/source, and coverage/use case. No unnecessary 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?

For a zero-parameter tool with no output schema, the description is entirely sufficient. It explains what data is returned, how fresh it is, where it comes from, and which ports are covered, making it complete for a user to decide to invoke the tool.

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 input schema has zero parameters, so the baseline is 4. The description adds no parameter-specific details because none are needed, but it does mention that it covers all major commercial crossings, which implies no filtering.

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 the tool's function with a specific verb and resource: 'Get real-time commercial border crossing wait times at US-Mexico and US-Canada ports of entry.' It distinguishes itself from siblings by focusing on border crossings and listing specific ports, making it unambiguous.

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 clear usage context ('Used by logistics companies, freight brokers, and trucking operations to route cross-border shipments through the fastest crossing points'), but it does not explicitly mention when not to use this tool or name alternative sibling tools for comparison.

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