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

With annotations already declaring the tool safe and read-only, the description adds value by enumerating exact output fields and the complete shipping_state enum. This goes beyond the generic title and gives the agent a clear picture of what data will be returned. No contradiction with annotations exists.

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 extremely concise: two short sentences that front-load the core purpose and then enumerate the output fields and state values. Every word earns its place, and the structure is scannable.

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 read-only tool with no output schema, the description compensates well by listing expected fields and the state enum. It does not explicitly state that some fields may be absent (e.g., tracking URL before dispatch), but the state enum implicitly covers this. Overall, the description is sufficient for an agent to understand what to expect.

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 input schema provides 100% coverage with detailed parameter descriptions, so the baseline is 3. The tool description does not add any information about parameter formats or relationships beyond what the schema already states. It neither improves nor detracts from the schema's clarity.

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 indicates this tool returns shipping information including carrier, tracking number, URL, ETA, and delivery status. The shipping_state enum adds specificity that distinguishes it from sibling tools like production_stage or pickup_status. However, it lacks an explicit verb like 'get' or 'retrieve', so the action is implied rather than stated.

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?

Usage is implied through the title and the data described (carrier, tracking, ETA), which clearly points to shipping-related queries. However, the description provides no explicit guidance on when to use this tool versus alternatives like vivid_fulfilment_order_status or vivid_delivery_estimate. No exclusions or alternative references are given.

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