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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly explains what the tool returns (compliance status, binding limit, maximum ATM, remaining payload), notes that it uses manufacturer specifications (not advice), and describes the key outputs. It does not cover data freshness, rate limits, or required permissions, but for a query tool these are not critical.

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 paragraph that is information-dense but somewhat lengthy. It front-loads the use case and then lists outputs, but could be more concise by splitting into shorter sentences. Every sentence provides value, but the overall structure is not optimal for quick scanning.

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 that there is no output schema, the description adequately explains return values (compliance status, binding limit, max ATM, remaining payload). It also clarifies the tool's scope (Australian vehicles, manufacturer specs, not advice). Minor missing details like data source update frequency prevent a perfect score, but it is largely complete for an agent to use 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 input schema already has 100% description coverage for all four parameters. The tool description adds little beyond repeating that 'load' is people+gear and 'variant' is trim. The description does not elaborate on how parameters interact or their defaults. Since schema coverage is high, a baseline of 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 clearly states the tool's purpose: to check legal towing compliance for Australian vehicles with caravans/trailers. It provides specific example queries and outlines the outputs (compliance status, binding limit, max ATM, remaining payload). The verb 'check towing' and the resource (vehicle+caravan) are explicit, and the description distinguishes the tool from potential alternatives by specifying its 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 explicitly advises when to use the tool ('Use when someone asks whether...') and provides typical user queries. Although no alternative tools are mentioned (no siblings), the context is clear enough for an agent to decide when to invoke it. It does not include explicit when-not-to-use guidance but the use case is well-defined.

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