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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false. The description reinforces this ('This reads state and moves nothing') and adds meaningful behavioral context by explaining the four possible statuses and what each means for the money (escrow, paid, returned, expired). It also notes that the read is 'live off the shop's rail', giving a sense of real-time data. This goes beyond the annotations without contradicting them.

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 detailed, explaining each status meaning, but it is front-loaded with the core purpose ('Where an order you opened stands'). It is somewhat long, but every sentence contributes to interpreting the tool's output, which is necessary because there is no output schema. The structure is logical, moving from status meanings to usage instructions.

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 no output schema, the description fully covers what an agent needs to interpret the tool's result: it enumerates the four possible statuses and their financial implications, explains the source of the order reference, and gives clear polling guidance. For a simple read-only tool with two parameters, this is complete.

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 100%, so both shop and order_ref are already described. The description adds value by specifying that order_ref is the one returned by checkout_intent, which clarifies the provenance of that parameter. It does not add other new semantics, so the baseline 3 is appropriate.

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: it reads the live status of an order and interprets what each status means for the money. It distinguishes itself from checkout_intent by explaining that checkout_intent returns an order reference that is then used here. The verb 'read' is explicit and the resource (order status) is unambiguous, making it easy for an agent to know when to call it.

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 provides explicit timing guidance: 'poll it after your human says they clicked the mail'. It also clarifies that it is a read-only operation ('moves nothing') and implies it should be used to obtain a receipt for the buyer. It does not name alternative tools or explicitly state when not to use it, but the context makes the intended usage clear.

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