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

Annotations already certify readOnly, idempotent, non-destructive, closed-world behavior, so the safety profile is covered. The description adds value by enumerating the returned data (status, items, estimate, tracking) and the input sourcing, which goes beyond the annotations. It does not describe failure cases (e.g., unknown reference), keeping it below 5.

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?

Two compact sentences with no filler, and the useful output description is front-loaded before the input requirements. Both sentences earn their 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?

For a simple two-parameter lookup with 100% schema coverage and annotations covering the safety profile, the description is nearly complete: it covers what is returned and how to source inputs. Error handling for invalid references is the only notable omission.

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 parameters are fully documented in the schema (8-char reference example, email used at checkout). The description largely restates these, adding only the source of the reference ('confirmation email'), so 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 states clearly what the tool returns for a single order (status states, items, delivery estimate, tracking), which makes its purpose obvious and distinct from siblings like get_product or search_products. It is not phrased as a clean verb+resource and doesn't explicitly name the siblings, keeping it just 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?

It tells the agent exactly what it needs to call the tool and where those inputs come from ('8-character order reference from the confirmation email and the email used at checkout'). This is strong prerequisite context, though there are no explicit when-not or alternative-tool conditions.

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