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

Adds substantial context beyond annotations: tax is an ESTIMATE, checkout uses full address for exact tax, nothing is opened or reserved, and delivery is limited to the 50 US states plus DC. These are key behavioral constraints for an agent.

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?

Front-loads the use case, then covers outputs, estimate caveat, read-only status, and geographic limits. Although dense, every clause adds decision-relevant information and there is no filler.

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?

No output schema exists, so the description appropriately explains the returned quote fields, estimate caveat, policy/checkout links, and geographic restriction. Combined with annotations, it is complete enough for an agent to call 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 50%, and the description adds useful meaning: destination is a US five-digit ZIP and state if known, and listing_id references an artwork/listing. It does not fully compensate for all nested schema gaps, but does enough to guide correct input.

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-like purpose—estimate delivered price and arrival for a work—and enumerates the returned quote components. It also distinguishes itself from purchase/checkout flows by saying it is read-only and that checkout calculates exact tax.

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 triggering condition: use when a buyer asks delivered cost and arrival timing. It also clarifies the checkout alternative for exact tax and notes the read-only, non-reserving behavior, so the agent knows when this tool is appropriate versus purchase-related siblings.

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