Track a parcel's delivery status

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

Annotations already provide readOnlyHint=true and openWorldHint=true. The description is consistent, stating 'Look up' which implies read-only behavior. No additional behavioral traits (e.g., rate limits, auth) are disclosed, so the description adds no extra value beyond annotations.

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 with two short sentences. Every word is informative and there is no fluff or repetition.

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 lookup tool with no output schema, the description is adequate but incomplete. It omits details about the response format, possible errors, and the courier parameter's role. This leaves some ambiguity for the agent.

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 0%, so the description must compensate. It lists three parameter names (consignmentId, invoice, trackingCode) and says to use any one, but does not explain their formats, constraints, or the courier parameter. The enum for courier is not mentioned. This provides only minimal semantic help.

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 states 'Look up the current delivery status of a parcel,' which is a specific verb+resource combination. It also distinguishes from sibling tools (list_couriers, create_parcel, etc.) by focusing on tracking.

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?

The description provides explicit guidance on parameter selection: 'Provide any ONE of: consignmentId, invoice, or trackingCode.' However, it does not discuss when not to use this tool or potential alternatives, but given sibling tools are very different, this is sufficient.

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