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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds useful context by enumerating the fields returned (brand, model, year, price, FIPE price, deal_score, ad URL), which is valuable given there is no output schema, but it says nothing about missing-id error behavior or response shape.

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?

A single front-loaded sentence: verb and resource first, then the field enumeration as justification for 'full details'. Nothing is redundant, though the attribute list is long enough to dilute the core action slightly.

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?

Because there is no output schema, the returned-field list is the description's main contribution and it is present. However, for a tool that overlaps heavily with get_listing_details, the absence of any routing guidance or not-found behavior leaves a clear gap.

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 0% and the schema only labels the parameter 'Car Id', so the description does carry some burden. It clarifies that the expected value is a 'PegaRex id', which is slightly more meaningful than the schema's generic integer label, but it gives no format, source or example of how to obtain one.

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 ('Fetch'), a precise resource ('full details of a single listing') and the identifier used to address it. It is distinguishable from list/search siblings, but it does not differentiate itself from get_listing_details, which appears to be a functional neighbor.

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?

There is no when-to-use or when-not-to-use guidance and no mention of the obvious alternative, get_listing_details, nor any statement about where the id comes from. The only implicit cue is 'by its PegaRex id', which hints that the id must be obtained elsewhere but does not say so.

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