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

Annotations already declare readOnly, openWorld, and non-destructive, so safety is covered. The description adds real value beyond them by disclosing that the call is billable and capped at 20 returned keywords, which is cost/scope context an agent needs before invoking.

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?

Two tight sentences with zero waste; the usage trigger is front-loaded and the cost/result caveat follows immediately.

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 read-only, billable API call with no output schema, the description covers when to use it, cost, and result ceiling. It stops short of describing the shape of returned keyword data or routing to sibling tools, but nothing critical for a correct invocation 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 75%, with target, languageCode, and locationCode all documented in the schema itself. The description adds no parameter-level detail (no mention of language/location or the limit parameter), so the baseline 3 is appropriate when the schema does the heavy lifting.

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 names a specific verb+resource: returns Google keywords a domain ranks for. An agent can distinguish it from dataforseo_google_serp and dataforseo_backlink_summary by the 'ranked keywords' framing, though it never names those siblings explicitly.

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?

It gives a clear when-to-use trigger ('when a team member asks which Google keywords a domain ranks for'), which is better than nothing. However, it offers no when-not-to-use guidance and does not point to the obvious alternative (dataforseo_google_serp) for SERP-level queries.

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