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

With no annotations, the description carries the behavioral burden and usefully discloses that this tool does not complete the order but returns an escalated checkout with a payment URL. It does not state whether the checkout state is mutated, what permissions are required, or what errors may occur, leaving important behavioral gaps.

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, front-loaded sentence that immediately clarifies the counterintuitive behavior and then states the return values. Every 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?

The description covers the key non-obvious outcome (escalation URL instead of order completion) and partially compensates for the lack of an output schema. However, given the nested `checkout` parameter, low schema coverage, and absence of annotations, it leaves too much unexplained about invocation and side effects.

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 description coverage is only 33%, and the description provides no information about the three parameters (`id`, `meta`, `checkout`). It does not clarify what `id` refers to, what the `checkout` object should contain, or how `meta` is used.

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 actual behavior: it returns the checkout with status `requires_escalation` and a `continue_url` for the buyer. It also explicitly clarifies that the store does not complete orders through the API, which prevents misinterpretation from the name `complete_checkout`. It does not explicitly contrast with sibling tools like `get_checkout` or `update_checkout`, so it falls short of a 5.

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?

Usage is implied: call this when completing a checkout requires escalation and the buyer must be redirected via `continue_url`. However, there is no explicit guidance on when to use this versus `get_checkout`, `update_checkout`, or other siblings, nor any stated preconditions.

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