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

Annotations already mark this as a safe read operation, but the description adds meaningful context beyond them: no login is required, both invalid email and invalid ticket return the same generic ORDER_NOT_FOUND error, and a different endpoint still requires OAuth. These details materially help an agent understand auth and error behavior.

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?

Four short sentences, front-loaded with the core purpose and followed by usage guidance and behavioral notes. Every sentence contributes useful information with no repetition or filler.

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 output schema exists, so return values need no explanation. Annotations cover safety, and the description covers the remaining critical concerns: authentication, error behavior, and when to prefer the sibling tool. The only minor omission is the optional lang parameter, but that is not essential for correct invocation.

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 description reinforces the meaning of the required parameters (buyer email and user-visible ticket/order_id), but the schema already documents both. With only 67% schema description coverage, the optional 'lang' parameter (enum en/es) is left unexplained in both schema and description, so the description does not fully compensate for the gap.

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 ('Guest order status') and a precise fallback condition ('when checkout_hash is gone'), which clearly distinguishes it from get_order_status. An agent can identify the tool's purpose 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?

Explicitly names the preferred alternative ('Prefer get_order_status with payment_link when the hash is still known') and states the no-login condition. It also clarifies that wrong email or ticket both return a generic error, setting expectations for failure modes.

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