delivery_estimate

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

With no annotations provided, the description carries the behavioral disclosure burden. It discloses an important nuance: the date is relative to the address, so both must be quoted together. It also clarifies the estimate is pre-order and per product. It does not explicitly state it is read-only, but 'estimate before ordering' strongly implies no mutation.

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 compact and every sentence adds value: the core output, the address-relative date caveat, and the sibling routing. The first clause is a slightly awkward fragment ('When a product would arrive...') rather than a clean verb phrase, which costs a point but does not harm clarity.

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 single-parameter tool with an output schema, the description provides the necessary context: what is estimated, the per-address date behavior, the pre-order scope, and which sibling tools cover adjacent cases. An agent has enough information to select and invoke the tool correctly.

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%, and the parameter description already explains that sku_or_url accepts a SKU or full product URL and that variants have their own SKUs. The tool description adds context that the estimate is per product, but it does not add significant parameter-level meaning beyond the schema, so 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 clearly defines what the tool provides: a delivery estimate for a product before ordering, including arrival date, target address, and source warehouse. It also distinguishes itself from list_orders() and get_checkout() by explicitly scoping it to per-product pre-order estimates, so an agent can tell it apart from siblings.

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 states exactly when to use this tool: per product, before ordering. It also names the alternatives for related scenarios, saying existing order dates are in list_orders() and checkout-formation dates are in get_checkout(), giving the agent clear routing guidance.

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