firestarter_shipping_estimate

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

Beyond the readOnlyHint and destructiveHint annotations, the description discloses that no execution, approval, or purchase occurs, that the returned rows are informational and not an approval menu, that street-less destinations may get estimate tiers, and that exact rates are re-quoted at approval. This significantly enriches the annotation-only picture.

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 dense and front-loaded with purpose and read-only status. It is longer than strictly necessary, but every sentence contributes operational guidance about inputs, outputs, or routing.

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 read-only estimate tool with no output schema, the description covers inputs, return contents, caveats, and related tools. Nothing essential is missing for an agent to invoke it 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%, but the description adds important selection logic: prefer address_id, use country+ZIP or city as fallback, no street address needed, and listing_id sources (preview, catalog, listings, share link). It also clarifies output meaning in the context of parameters.

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: estimate shipping for a listing before purchase. Explicitly differentiates from firestarter_execute and firestarter_shipping_options by clarifying this is informational and not an approval or purchase path.

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?

Explicitly says when to use it: while the buyer is browsing, to answer 'how much is shipping?' or 'can this ship to me?'. Also gives exclusions and alternatives, directing actual purchase to firestarter_execute and post-order shipping to firestarter_shipping_options.

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