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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so safety is covered. The description adds real value beyond that by enumerating the data returned (recommended vs optional portal, home page, listing form, private-seller fee with source, payment service, foreign-seller eligibility), which matters since there is no output schema.

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?

One sentence, front-loaded with the resource and then a compact list of returned attributes; each clause contributes information. The parenthetical country list is slightly redundant with the schema enum.

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 is doing the necessary work of explaining what each portal entry contains, and the only parameter is fully documented in the schema. An agent has everything needed to call it and interpret results.

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 the single country parameter has an enum plus the note 'Optional: only this country'. The description merely restates the same country list as the enum, adding no semantics beyond what the schema already provides, so the baseline 3 applies.

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 resource (car portals AutoPrivado prepares posting kits for, per country) and enumerates the attributes each entry carries, so an agent knows exactly what this returns. It doesn't explicitly contrast with siblings, but none of them (create_listing, get_listing, search_listings, etc.) cover portal data, so confusion risk is low.

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 only implied: the agent can infer this is a reference lookup for portal/posting-kit information, and the optional country parameter signals 'all countries by default, one if specified'. There is no explicit when-to-use statement, no exclusions, and no named alternative tool.

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