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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the safety profile is covered. The description adds valuable behavioral context: opening the link adds the arrangement to the cart and opens the cart panel, and the customer completes checkout. This goes beyond the annotations and helps the agent understand side effects on the user's session.

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, well-structured paragraph that front-loads the core purpose and then explains conditional behavior. It is slightly long but every sentence adds meaningful information about the link's behavior and the checkout flow.

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 tool with no output schema, the description explains what the return value contains (purchase link plus price breakdown) and the conditional additions. It also covers the downstream effect of opening the link. It does not specify the exact format of the link or breakdown, but the description is sufficient for an agent to invoke the tool and understand the result.

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 description coverage is 100%, so the schema already documents all four parameters. The description adds context about how zip and date affect the breakdown (exact delivery fee, tax, order total, delivery availability), which is useful but not essential since the schema already covers the parameters. Baseline 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 states a specific verb ('Return'), a specific resource ('purchase link for an arrangement'), and adds a price breakdown, which clearly distinguishes it from siblings like check_delivery and search_arrangements. The title reinforces the purpose without being a tautology.

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 explains when to include a ZIP and a date, and implies the tool is for generating a purchase link rather than checking delivery or searching. It does not explicitly name alternatives or state when not to use it, but the context is clear enough for an agent to select it correctly.

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