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

Annotations cover the safety profile (not read-only, idempotent, non-destructive), and the description adds meaningful operational context beyond them: the mandatory human-in-the-loop payment step ('Never submit payment for them'), the need to persist order_id and order_capability before sharing confirmation_url, and the session-loss recovery path via get_order. This is strong supplemental disclosure.

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 purpose and code-handling guidance are reasonably front-loaded, but the confirmation_url instruction is split and partly repeated ('Give confirmation_url to the person to review codes and pay themselves' then 'before passing confirmation_url to the person'). Efficient enough but with redundancy that could be tightened.

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 7-parameter order tool with low schema coverage and no output schema, the description covers the human payment workflow and post-payment recovery well, but leaves most required parameters (quote_id, expected_revision, idempotency_key, capabilities) unexplained. It is adequate on process but incomplete on inputs.

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 14% across 7 parameters, so the description must compensate but largely does not. It explains coupon_codes semantics (renewal/referral/channel codes and valid/invalid status), but leaves quote_id, expected_revision, request_id, request_capability, and idempotency_key entirely undocumented. Most parameter meaning is missing.

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 conveys that this prepares an order for the final quote, adds coupon codes, and yields a confirmation_url for the person to pay. But the opening verb 'Read or update the order' is muddled against the name create_order and title 'Prepare order,' and it never differentiates this from siblings like start_order or confirm_quote. Purpose is inferable but not crisp.

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 gives explicit procedural guidance: pass coupon codes before payment starts, hand confirmation_url to the person, and never submit payment on their behalf. It also routes to the alternative get_order 'after payment, even if the original session is lost.' It stops short of stating when to choose this over start_order/confirm_quote, but the when/when-not framing is largely present.

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