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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so safety is clear. The description adds scope and ordering ('newest first'), but does not mention pagination, return shape, or whether results are capped by the limit parameter.

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?

A single focused sentence with no wasted words. The key scope and ordering information is front-loaded.

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 read-only listing tool with no required parameters, full schema coverage, and clear annotations, the description is largely sufficient. It could be improved by noting pagination or maximum result behavior, but the schema already covers the limit cap.

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 parameters like limit, carrier, dateFrom, and intentId are fully documented in the schema. The description adds no extra parameter semantics beyond what the schema provides, which is the baseline expectation when coverage is complete.

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 a specific verb and resource: 'List the most recently created shipping labels,' with scope ('in your scope') and ordering ('newest first'). It is clear what the tool returns, though it does not explicitly differentiate itself from sibling tools like SearchShippingLabels or FindLabel.

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 phrase 'most recently created' implies a use case for recent-label lookups, but there is no explicit guidance on when to choose this tool versus SearchShippingLabels, GetLabelsForOrder, or FindLabel. Usage is implied rather than directed.

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