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

Annotations already establish a safe read-only, non-destructive, closed-world operation, yet the description adds substantial behavior: the meaning of `unresolved` values, that `reason` is the platform's own wording, that "calculated manually" implies no quote exists, the manual-quote path, and the included_miles/per_mile_usd tiering with the 1,500-mile limit. This is well beyond what annotations cover.

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-loaded with the core deliverability question before edge cases. It is long and dense, but most sentences carry non-obvious pricing rules that the agent needs; a few clauses could be tightened, keeping it just under the top mark.

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?

With no output schema, the description carries the full burden of explaining return values (unresolved, reason, needs_manual_quote, included_miles, per_mile_usd) and it does so thoroughly for a complex domain. An agent has enough to interpret results and act on the manual-quote case.

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 both parameters are fully documented in the schema, so baseline is 3. The description adds only indirect value, clarifying that a bad `origin` means no destination value the buyer supplies will help, but adds no syntax or constraints beyond the schema's ZIP / "City, ST" spec.

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 up front: whether a listing can be delivered to a destination, what delivery adds to buyer_price_usd, the distance, and the total. An agent can distinguish it from pricing siblings (pricing_quote_payout, pricing_quote_crosslist) without opening the schema.

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 conditional routing for the no-quote case (needs_manual_quote is true, so contact support via support_create_ticket or the support line), which is genuine when-to-use guidance. It does not explicitly contrast with pricing_get_guide or state when delivery quoting is preferred over other pricing calls, so it falls short of full 5-level guidance.

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