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

Annotations already declare destructiveHint=true, openWorldHint=true and idempotentHint=false; the description earns credit for adding what those flags cannot: revalidation of the frozen item, price and destination, the fact that an external artifact (URL handoff, Square payment link, Shopify checkout) is created, and that Onhand never takes payment. It stops short of covering failure/retry behavior or whether a created link can be revoked.

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 tight sentences, front-loaded with the core action, then the side effects, then the payment-responsibility caveat. No filler 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?

With one parameter and no output schema, the description carries the burden of explaining outcomes, and it names the three possible handoff results plus the payment boundary. It leaves the agent guessing slightly about the return payload and what happens on revalidation failure, but covers the decision-relevant surface.

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 single parameter has 0% schema description coverage, but the description compensates by explaining that 'intent' is the opaque token returned by prepare_checkout and that it encodes frozen item, price and destination. That is real meaning beyond the schema's bare string constraint, though the maxLength/format expectations remain undocumented.

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?

States a specific verb and resource ('Confirms a prepared checkout') scoped by 'once using the intent from prepare_checkout', which cleanly separates it from the sibling prepare_checkout. An agent can tell exactly what this tool does without opening the schema.

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 prerequisite is explicit: it consumes the intent produced by prepare_checkout, and 'once' signals it is a single-shot confirmation. It does not state when not to use it or what to do if the confirmation fails, which keeps it short of a 5.

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