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

Annotations only cover the read-only/idempotent safety profile; the description adds cost behavior (no credit deduction, free selection card, free catalog verification), default 365-day history, what a result contains (wholesale, retail, and new-car risk reference, delivered as a native card rather than HTML), and the special account_connection_required delivery path. None of that is derivable from the annotations, and nothing contradicts them.

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 key routing rule is front-loaded, which is good, but the body is a dense run-on block that interleaves parameter guidance, fallback behavior, delivery format, and terminology rules (product naming, 'not non-store quote' phrasing). Several sentences serve presentation policy rather than tool selection, and the lack of structure makes the operative instructions harder to extract.

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 nested-schema, no-output-schema tool, the description covers the important behavioral contract: default history window, no-guess fallback, card delivery, and account-connection handling. It is only incomplete on the many numeric/filter fields inside `query`, which an agent would have to infer from names alone.

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 0%, so the description must carry parameter meaning. It does explain `vehicle` (brand+series or hints like C300), that all explicit conditions go in `query` and no model_id is passed, how `trim` accepts user configuration hints, and the 365-day history default. But city, province, model_year, price/mileage ranges, limit, time_basis, max_age_days, and response_mode are left entirely undocumented, so the compensation is only partial.

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 action chain: auto-identify the real model ID, match existing model-year trims, and query market prices in one call. It also explicitly names the sibling tools it replaces (resolve/choices/capabilities/access), so an agent can tell this apart from those tools without opening any 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?

It says explicitly not to pre-call resolve/choices/capabilities/access, tells the agent what to put in `vehicle` versus `query`, and states that ambiguous or multi-candidate input returns a free selection card instead of guessing. That is when-to-use, when-not-to-use, and fallback routing all in one place.

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