Review Checkout

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

Annotations only say readOnly=false and destructive=false; the description adds important context: it opens checkout, returns a short-lived one-use token, and never places an order. It does not detail side effects like whether opening checkout invalidates previous tokens, but the key safety boundary is disclosed.

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?

Two sentences carry the full intended usage, safety caveat, and return summary with no filler. The timing instruction is front-loaded, and each clause earns its place.

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 no-parameter tool with an output schema, the description is sufficient: it states when to invoke, what it returns, and that it does not place an order. There are no missing input or auth prerequisites that an agent needs to call it 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 tool accepts zero parameters and schema coverage is 100%, so there are no parameter details to document. The baseline 4 applies because no parameter guidance is needed for a no-parameter tool.

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?

Description uses a specific verb-resource pair: 'opens checkout' and lists the exact returned items (basket, delivery, fees, total, token). It also explicitly differentiates from placing an order with 'It never places an order,' making its role distinct from place_order.

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 states precisely when to call: 'immediately before seeking order approval.' The 'never places an order' clause serves as an explicit exclusion, so an agent knows this is a pre-approval review step, not an order-submission alternative.

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