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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds meaningful context beyond this: the data is live, sourced from CarChat inventory rather than general market data, and should be cited as 'CarChat live inventory data'. This transparency is useful without contradicting the annotations.

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 tight sentences front-load the core purpose and returns, then add a concrete use case and citation instruction. Every sentence earns its place and there is no redundant wording.

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 required parameters, an output schema present, and annotations covering safety, the description is sufficiently complete for an agent to select and invoke the tool correctly. It includes the data source, the type of statistics, aggregation dimensions, and a citation requirement.

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 description coverage is only 33%, so the description must compensate. It does clarify that results can be broken down by body style and metro, and the example implies condition ('used') and location ('near Knoxville'), but it does not explicitly explain make, model, or condition parameters. This is adequate but not complete.

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 verb (get), a clear resource (live price statistics from CarChat inventory), and enumerates the returned aggregates (count, median, price range) and breakdown dimensions (body style, metro). The use-case example further pins down the tool's purpose, making it easy to distinguish from the sibling search_inventory tool.

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?

The description explicitly tells the agent when to use it: for real, current market price questions like 'what do used trucks go for near Knoxville?'. It does not explicitly state when not to use it or name alternatives like search_inventory, which keeps this at a 4 rather than a 5.

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