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

With no annotations, the description carries the full burden and does disclose useful traits: the geographic/dealer restriction (franchise dealerships only, Brand Boulevard), the return payload (price, mileage, dealer, link), and the pricing caveat (dealer-set, excludes tax and fees). It does not cover pagination behavior, result caps, empty-result handling, or whether inventory is exhaustive, which are relevant for a 13-parameter search.

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?

Three short sentences, front-loaded with what is searched and where, followed by return contents and the pricing caveat. Every sentence earns its place; the only minor inefficiency is that the price disclaimer is not framed as guidance pointing at out_the_door_price.

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 13-filter search tool with no output schema and no annotations, the description covers the essentials: scope, returned fields, and price semantics. Pagination/result-count behavior and inventory completeness are the remaining gaps, but an agent has enough 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?

Thirteen parameters exist with only 54% schema description coverage, and four enum fields plus two undocumented numeric filters (year_min, miles_max, price_min/max partly) rely on the schema alone. The description adds no meaning about what 'q' searches over, how filters combine, or how sorting/paging interact — the only implied link is that price and mileage are returned fields, so mileage/price filters exist. It does not compensate for the coverage gap.

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+resource ('Search new and used cars for sale') with tight scope: franchise dealerships on Brand Boulevard in Glendale, CA. An agent immediately knows this is a listing search, not a detail lookup. It does not explicitly name how it differs from siblings like get_car or out_the_door_price, so it stops short of 5.

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?

Usage is implied by 'Search' vs the sibling get_car (single-vehicle retrieval), and the note that prices exclude tax and fees faintly gestures at out_the_door_price. But there is no explicit when-to-use/when-not-to-use statement or direct routing to the alternative tools, leaving the agent to infer the boundary.

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