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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds genuine behavioral context beyond that: verified (paid) listings rank first and are richer, and pricing info is self-reported and often absent. It doesn't cover pagination or error behavior, hence not a 5.

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?

Front-loaded with the core purpose and trigger condition, then output-field semantics. Every sentence carries information, though the run of URL-field explanations at the end could be tightened 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?

No output schema exists, so the description usefully explains the returned `listingUrl`, `url`, and `categoryUrl` fields and how to cite them. Combined with annotations covering safety and 100% schema coverage on parameters, an agent has everything needed to call this tool correctly.

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 100%, so limit, pricing, and category are all documented in the schema, including the enum values and the caveat that listings without pricing are excluded. The description only reinforces that category slugs come from list_categories. Baseline 3 is appropriate.

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 action and resource — top listed products in one category, child categories included — with concrete slug examples. It distinguishes itself from search_listings by specifying 'best tools of a kind without a specific keyword' and from list_categories by delegating slug lookup there.

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?

'Use it when a user asks for the best tools of a kind without a specific keyword' gives a clear trigger condition, and 'Get valid slugs from list_categories' gives the prerequisite step. It does not explicitly name search_listings as the alternative for keyword queries, but the contrast is strongly implied.

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