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

No annotations are provided, so the description carries the burden of behavioral disclosure. It discloses that the tool errors if prerequisites are missing, that the customer lands on a review summary, and that the agent never handles payment. It could further state the return format or side effects, but for a checkout-link builder the disclosed behavior is substantial.

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?

Three sentences, each earning its place: what it builds, hard prerequisite with failure mode, and what the customer/agent experience is. Front-loaded with the purpose, then the most critical constraint, then the payment context. No fluff or repetition.

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?

The tool has 10 params and nested objects, but the schema covers them well and the description ties them to upstream tools. With no output schema, the description could clarify the return payload more, but it explains the customer-facing outcome well enough. Missing explicit return-structure docs is the main gap.

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 90% and the schema already describes each parameter. The description adds context beyond schema: it explains which parameters come from get_purchase_requirements and emphasizes that vehicle/insured/next_of_kin are required collectively even though they're not marked required in the schema. This compensates for the schema's shallow 'required' list.

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 what the tool does: 'Build the MIB hosted-checkout link for a chosen offer (from compare_insurance_quotes).' It specifies the verb (build), the resource (hosted-checkout link), and the precursor (offer from compare_insurance_quotes), which also distinguishes it from sibling tools like get_purchase_requirements or compare_insurance_quotes.

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 explicitly says when to use: with an offer from compare_insurance_quotes, and only after get_purchase_requirements has collected full details. It even warns that without those details the tool returns an error telling you what to collect, effectively providing a when-not-to-use condition. This is clear contextual guidance.

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