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

Annotations already cover read-only, idempotent, non-destructive and closed-world behavior, so the bar is lower. The description still adds meaningful context the annotations cannot: results are explicitly labelled advertising or first-party services, include canonical links, and no payment action occurs — useful disclosures about result nature and absence of side effects.

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 dense sentence with the resource scope front-loaded and every clause carrying information (labelling, canonical links, no payment). Nothing is redundant or padded.

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 simple no-required-param, read-only listing tool with full annotation coverage and no output schema, the description supplies the essential context: what the results are and how they are marked. The only real gap is the unmentioned limit/pagination dimension.

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 description never mentions the single 'limit' parameter, its 1–100 range, or any pagination behavior. With one undocumented parameter the description must compensate, and it does not, leaving the agent to infer semantics from the bare schema.

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 and resource ('List currently highlighted services') with a qualifying scope that distinguishes it from the sibling listing tools by content type (sponsored/own services). It never names a sibling explicitly, so an agent must infer the boundary against discover_listings on its own.

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 qualifier 'paid sponsorship or the publisher's own service' implies the use case (surfacing commercial placements rather than organic listings), but there is no explicit when-to-use, when-not-to-use, or pointer to discover_listings/get_listing as alternatives.

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