pay_shipment

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

No annotations are provided, so the description must convey behavioral traits. It states payment and label generation, but does not mention irreversibility of payment, required shipment state, error scenarios, or potential destructive effects. The absence of side-effect disclosure is a significant gap for a financial operation.

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 a single concise sentence that covers the core action. However, it could be restructured to highlight the prerequisite (rate selection) and optional component more clearly. Still, it is efficient with minimal waste.

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?

With no output schema, the description should explain what is returned (e.g., label details, confirmation). It also omits important context like required shipment state (must be in draft?), idempotency, or consequences of failure. For a payment tool, completeness is insufficient.

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%, providing adequate parameter descriptions (e.g., rate_id source, insurance object fields). The description adds only that insurance is optional, which is already implied by the schema's optional flag. No further semantic value beyond the schema is provided.

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 explicitly states the action (pay, generate label) and the resource (selected rate shipment), with mention of optional insurance. It clearly differentiates from siblings like buy_label_from_order or create_draft_shipment, as it specifically handles payment after rate selection.

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 implies usage after get_shipping_rates by referencing 'selected rate', but does not explicitly say 'use after get_shipping_rates' or when not to use (e.g., already paid). No comparison with alternative tools like buy_label_from_order is provided.

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