XMLStock: serp

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

The description discloses critical behaviors beyond annotations: every request is billed, pagination creates additional paid requests, empty results still cost money, mobile responses omit hlword/PAA/related, and yandex_xml returns different stats and fields. No statement contradicts the annotations; readOnlyHint=false is consistent with paid 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?

The description is dense but front-loaded with purpose, billing, and response shape. Some paid-request warnings are repeated, and the single-block format could benefit from headings or bullet separation, but every section serves a functional purpose and no filler is present.

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?

With no output schema and 17 parameters, the description carries the full burden of explaining return values and constraints. It covers found/truncated/count/results/serp_features, empty-result behavior, engine-specific output fields, pagination, and source limitations. This is complete enough for reliable invocation and interpretation.

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?

Even though schema coverage is high at 82%, the description adds substantial parameter-level meaning: depth pagination behavior, region working across all engines, mobile-specific restrictions, non-applicable parameters for yandex_xml, and safeSearch-to-filter mapping. This goes well beyond what the JSON schema alone provides.

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 clearly identifies the tool as a snapshot of Google/Yandex SERP via XMLStock and immediately distinguishes it from image/news/video siblings by describing organic results and serp_features. It also explicitly names engine variants and their semantic differences. This is a specific verb-resource pairing that an agent can act on without ambiguity.

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 selection guidance between engine values, especially yandex_xml versus yandex (live), listing non-applicable parameters and safeSearch mapping. It does not explicitly tell the agent when to choose this tool over sibling tools like xmlstock_images or xmlstock_news, so it falls just short of a 5.

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