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

Annotations only declare readOnlyHint and openWorldHint; the description adds substantive traits the agent could not infer: data is fetched via residential proxy, pagination caps at page 10, ~20 results per page, and a pay-per-call x402 model at $0.002 USDC with failed calls not charged. The last point is operationally important, telling the agent retries are free.

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?

Purpose and scope come first, followed by return fields, paging, source and pricing — a sensible front-loaded order. The long enumeration of returned fields is dense but each item is substantive, and nothing is truly wasted; it is slightly heavy for a single sentence.

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 two-parameter filtered search, everything an agent needs is present: what it searches, where the data comes from, field coverage, paging limits, result count, and the cost/charging model. An output schema exists, so the field enumeration is bonus rather than a gap-filler.

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%, so both parameters are already documented, including the 'page 1 to 10 (default 1)' constraint. The description restates the page range and adds only the ~20-per-page result size, which is marginal added meaning over the schema; 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 verb (search) and a precisely scoped resource: Nykaa India beauty products. The parenthetical '(India)' and 'nykaa.com' differentiate it from the many generic beauty/marketplace siblings such as sephora_products or openbeautyfacts_products without opening a schema.

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 geographic and vertical scoping ('Nykaa (India) beauty product search', 'from nykaa.com') gives clear context for when this tool applies rather than a regional or global alternative. It stops short of naming a specific sibling to prefer or stating when not to use it, so it falls just below an explicit routing statement.

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