Merge parcel labels

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

Annotations already declare non-destructive behavior. The description adds that the tool merges already-generated labels and returns a URL, which is helpful context. It does not elaborate on permissions or rate limits, but the operation is simple enough that the added constraint 'only works for existing labels' is sufficient.

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 sentences cover purpose, output, and constraint. No wasted words. Information is front-loaded and easy to parse.

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 merge tool with one parameter and no output schema, the description adequately explains the input constraint, the operation, and the return value. It is complete for an AI agent to understand when and how to use it.

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%, with a well-described parameter (ids: array of shipment_order_ids). The description does not add any additional meaning beyond what the schema provides, so the baseline score of 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 uses a specific verb ('Merge') and resource ('parcel labels') and states the output ('single PDF URL'). It clearly distinguishes from sibling tools, which deal with creating, shipping, or voiding orders, not merging existing labels.

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 explicitly says 'Only works for labels that already exist,' providing a clear usage constraint. However, it does not mention explicit alternatives or when not to use it beyond that constraint.

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