printful_calculate_shipping

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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=true, covering safety and idempotency. The description adds value by specifying what the tool returns ('available shipping methods, costs, and estimated delivery times'), which isn't in the annotations. However, it doesn't disclose additional behavioral traits like rate limits, authentication needs, or error conditions, keeping the score moderate.

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 and well-structured: two sentences that front-load the core action and then detail the return values. Every word earns its place, with no redundancy or fluff, making it easy for an agent to parse quickly.

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?

Given the tool's moderate complexity (calculating shipping with multiple inputs), the description is reasonably complete. It explains the purpose and output, and with annotations covering safety and an output schema presumably detailing return values, major gaps are filled. However, the lack of usage guidelines and deeper behavioral context (e.g., error handling) prevents a perfect score.

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 has 0% description coverage (since the top-level 'params' property lacks a description), but the nested 'CalculateShippingInput' schema provides detailed descriptions for all parameters. The description doesn't add any parameter-specific semantics beyond what's in the nested schema (e.g., it doesn't explain 'items_json' format or 'currency' defaults). With the nested schema doing the heavy lifting, 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 clearly states the tool's purpose: 'Calculate shipping rates for an order.' It specifies the verb (calculate) and resource (shipping rates), making the function unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'printful_confirm_order' or 'printful_create_order', which might also involve shipping considerations, so it doesn't reach the highest score.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing order items first), compare it to sibling tools (like 'printful_create_order' which might handle shipping), or specify scenarios where it's appropriate (e.g., pre-order estimation vs. final checkout). This leaves the agent without contextual usage cues.

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