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

Adds meaningful behavior beyond annotations: it does not pay or place an order, and it should only be used when the user wants a purchase link. It also explains design omission and exact-design-object requirements, though it does not fully explain the destructive session-overwrite implication already hinted by destructiveHint=true.

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 purpose is front-loaded, then usage constraints and design-object handling follow in a compact sequence. Every sentence contributes actionable guidance without 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 complex, nested, destructive/open-world tool, the description covers the main action, usage condition, design payload integrity, and the no-payment caveat. It stops short of describing the return value or explicitly warning about session-content overwrite, but the schema and annotations fill much of that gap.

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 the baseline is 3, but the description adds important semantics for the options.designs path: omit designs to use approved session designs, or pass exact complete returned design objects and do not reconstruct name/size-only entries. This materially reduces misuse of the nested design payload.

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?

States a specific verb and resource: save selected session designs and create one Shopify basket/checkout link with names, sizes and quantities. It clearly distinguishes this from design-editing siblings by emphasizing the purchase link outcome.

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?

Gives a clear usage condition: 'Only create it when the user wants a purchase link', and clarifies that omitting designs uses approved session designs. It does not explicitly name alternatives such as preview_design or validate_design, so it falls short of a full 5.

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