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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds the auth prerequisite (Authorization: Bearer mo1_… or the ref argument) and notes the pending-until-email-confirmed lifecycle, which is useful beyond annotations. It does not describe rate limits, error behavior, or what happens with an invalid/expired reference.

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 first sentence front-loads the return payload and the second gives usage and auth prerequisites, so the structure is logical. The parenthetical lifecycle list is dense but informative; the auth parenthetical slightly duplicates the schema.

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 single-optional-parameter read tool with no output schema, the description covers the return payload, lifecycle states, auth requirement, and triggering situations. Missing only minor details such as behavior on an invalid reference or pagination (unlikely needed here).

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%, and the schema already explains that ref is the mo1_… reference used only when the client cannot send the Bearer header. The description repeats the auth alternative without adding format or precedence detail beyond the schema, so the baseline of 3 applies.

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 names a specific resource (the order reference) and enumerates exactly what it returns: order state, email confirmation, cart lines and totals, remaining checkout needs, and next step. It is clearly a read/status tool distinct from siblings like view_checkout or check_payment, though it does not explicitly contrast itself with those siblings.

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 states concrete triggers: 'Use it to resume an order and after the shopper says they confirmed the email.' That gives clear when-to-use context. It does not name which alternative to use instead when the shopper has not yet started an order, and there are no explicit exclusions versus view_checkout or order_history.

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