book_order

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

The description indicates the tool returns an orderIdentifier, which is useful. However, since no annotations are provided, the description carries full burden for behavioral disclosure. It does not mention mutability, side effects, prerequisites (e.g., account setup), or error conditions. It is adequate but not comprehensive.

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 sentence with 15 words, front-loading the key action and outcome. Every word serves a purpose. No filler or redundancy.

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 tool's complexity (17 parameters, nested objects, no output schema), the description is concise but omits details like what happens on failure, pricing implications, or whether label retrieval is synchronous. However, the schema is well-documented, and the return value is stated. The description is nearly complete for the tool's core function.

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 100% description coverage, meaning all parameters include descriptions. The tool description itself does not repeat parameter details, but the schema already provides sufficient meaning. However, the description highlights the return value (orderIdentifier), which adds context beyond the schema. Given high schema coverage, baseline is 3, but the explicit mention of the return value and the tool's core action adds value, justifying a 4.

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 book a Royal Mail shipment via Click & Drop. It specifies the action (book), resource (shipment), and the system (Click & Drop), and mentions the return value (orderIdentifier). This distinguishes it from siblings like cancel_order, get_label, etc.

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 does not provide explicit guidance on when to use this tool versus alternatives like cancel_order or list_services. It implies usage for booking shipments, but no exclusions or alternatives are mentioned. The context of sibling tools is present, but the description lacks explicit usage instructions.

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