xmlstock_serp

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

With no annotations, the description fully carries behavioral disclosure. It reveals that empty results are still billed (code 15), depth>10 triggers separate paid pages, mobile omits hlword/PAA/related, and region is passed to both engines. It also details the exact return shape, including serp_features, demonstrating high transparency.

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?

The description is dense and long, but every sentence carries essential operational knowledge (return structure, billing, region, device restrictions). It is front-loaded with purpose and return info, and the length is justified given the tool's 17 parameters and complex behavior. A slight split into paragraphs could improve readability, but it remains efficient.

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?

There is no output schema, so the description compensates by fully specifying the return object and fields. It covers critical edge cases (empty results, truncation, pagination), engine-specific features, and the all-important billing caveat. For a complex paid SERP API, this description is unusually complete and self-sufficient.

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 82%, so the baseline is 3. The description adds valuable semantics beyond the schema: depth>10 pagination cost, region mapping for both engines, device=mobile limitations, and the empty-result payload. This meaningfully enriches parameter understanding, though the schema itself already documents many parameters well.

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 opens with 'Слепок выдачи Google/Yandex через XMLStock' (a snapshot of Google/Yandex SERP via XMLStock), clearly identifying the specific verb+resource. It distinguishes from sibling tools (images, news, video, wordstat) and notes the paid-per-request nature, leaving no ambiguity about what the tool does.

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 description gives strong contextual guidance: it is for SERP snapshots, with explicit notes on paid pagination for depth>10, single-region behavior for both engines, and the mobile/desktop limitation. It does not explicitly name alternative tools for exclusion, but the sibling names and core purpose make the intended use clear.

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