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

Goes well beyond the readOnlyHint/openWorldHint annotations: it discloses the ~20-item cap, that data comes through a rendering residential proxy (hinting at latency/failure modes), and precise cost terms — $0.02 USDC per successful call via x402 on Base, Solana or Arc, with failed calls not charged. That payment and billing behavior is information an agent cannot get anywhere else.

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 paragraph, front-loaded with what is returned, then the category format, then source/proxy and pricing. No filler sentences; every clause carries actionable information.

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 single-parameter scraping tool with an output schema already covering return shape, the description supplies the remaining essentials: the result cap, the exact category identifier format, the data source, and the payment model. Nothing an agent needs before calling is missing.

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 parameter is already documented with the same id/slug format, so the schema carries most of the load. The description nonetheless reinforces the semantics by supplying three varied category examples (81/vitamins-supplements, 1093/cold-flu, 109/foot-care), making the id/slug pattern unambiguous.

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 concrete resource (Chemist Warehouse Australia category products) and enumerates exactly what is returned: id, name, AUD price, saving off RRP, rating/review count, image, link. Scope is pinned down as 'first page, about 20'. It does not explicitly contrast itself with sibling site-scrapers, but the site-specific naming makes the distinction obvious.

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 implied rather than stated: the 'first page, about 20' note tells the agent this cannot paginate, and the category examples show the accepted input shape. There is no explicit when-to-use or when-not rule, and no guidance on what to do if more than 20 products are needed.

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