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

Annotations already declare readOnlyHint=true and idempotentHint=true, and the description's 'Return' is consistent with those. It adds limited behavioral context beyond that—primarily the data payload—but does not cover authentication, error behavior, or what happens if the listing does not exist; acceptable for a simple read but no extra depth.

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 sentence of 14 words that is front-loaded with the action and object, followed by specifics. No filler or redundant restatement of the tool name.

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?

Given an output schema exists and only one required UUID parameter, the description's listing of return fields is likely sufficient for an agent to invoke it. The main gap is not contextualizing the tool against its many siblings, but that is already captured in usage_guidelines; overall completeness is good for this complexity.

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?

The only parameter, id, is a UUID with no schema description, and the description does not explicitly explain how id maps to a listing. However, the title and the phrase 'Return one paid listing' combined with the required id make the mapping inferable. Since schema coverage is 0% but there is only one obviously named parameter, this is adequate but not compensated beyond the obvious.

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 uses a specific verb ('Return'), identifies a concrete resource ('one paid listing'), and enumerates the exact data returned (rank, verified payer identity, declared machine endpoints). It clearly distinguishes a single-listing lookup from sibling tools like search_agents by emphasizing 'one' and 'paid'.

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?

No guidance is given about when to call this tool versus alternatives such as search_agents or inspect_organic_resource. It does not state what problem it uniquely solves or any exclusions, leaving selection to inference.

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