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

Annotations already declare readOnly/openWorld/idempotent/non-destructive, yet the description adds what annotations cannot: the call draws on the agency's own DataForSEO account, incurs a small monetary cost per call, reports that cost and the monthly limit consumption in the response, and confirms day-scoped caching is free. That is exactly the extra context an agent needs for cost-aware invocation.

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?

Three sentences, no waste, and the highest-value information — what you get and what it costs — is front-loaded. Cost and caching behavior follow in a logical order.

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, and the description compensates by listing the returned fields and disclosing that cost and monthly-quota usage are reported in the answer. Combined with 100% schema coverage and rich annotations, an agent has everything needed to invoke it 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%, with per-parameter descriptions covering depth, keyword, language and location including examples. The description only echoes scope at a high level ('one market', 'up to 30 results') without adding format or default guidance beyond the schema, so the baseline 3 applies.

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 and resource — live Google organic results for a keyword in one market — plus the exact fields returned (position, title, address, snippet) and the 30-result cap. It is clearly distinct from the site-ownership siblings like seo__rankings or seo__ranked_keywords, but it never names an alternative, so differentiation is implied rather than explicit.

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?

Gives real decision context an agent needs before calling: it spends the agency's own DataForSEO budget, and a repeat query within a day is served free from Royally's copy. That effectively tells the agent to reuse/repeat rather than fear cost. It stops short of naming when-not-to-use or pointing at a specific alternative tool.

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