keywords_for_site

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

No annotations are provided, so the description carries the full behavioral burden, and it does disclose one genuinely important trait: the tool costs 0.05 USDC on Base via x402, i.e. it is a paid call. That is real value beyond the schema. It still omits return shape, latency, or what happens on a repeat request, so with zero annotation coverage the picture is only partially complete.

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?

A single front-loaded sentence with the core purpose first and the cost caveat trailing. The nested parentheticals ("(Google Ads data)", "(costs 0.05 USDC on Base via x402)") are slightly cluttered but every clause earns its place.

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 5-parameter paid tool with no annotations, no output schema, and only 40% schema coverage, the description should carry much more: return contents, what the pricing/permission model means for callers, and clarification of the undocumented locale/limit params. It covers only purpose and cost.

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 only 40%: target and confirmNewPurchase are documented, but limit, language_code, and location_code are not. The description adds nothing about any parameter, so it fails to compensate for the coverage gap, landing below the baseline-3 threshold that high coverage would have justified.

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?

"Keywords a website SHOULD target, derived from its content (Google Ads data)" names the specific resource (target keyword suggestions) and the derivation method, which is more than a tautology. However, it does nothing to distinguish itself from keyword-adjacent siblings such as keyword_ideas, keyword_metrics, or ranked_keywords, so an agent cannot tell which sibling to pick from the text alone.

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 states what the tool produces but gives no when-to-use guidance, no exclusions, and no reference to alternatives like keyword_ideas or ranked_keywords. The only implied usage cue is "derived from its content", which is a data-source note rather than routing guidance.

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