Keyword search volume

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description usefully discloses what data comes back (trend, competition, bid range), which matters because there is no output schema, but it omits operational traits such as the 10,000-keyword cap, billing/quota implications, or latency for large batches.

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 sentence that front-loads the returned metrics and closes with a concrete use case. Every clause carries information; nothing is redundant or padded.

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, the description correctly spends its words enumerating the returned metrics and clarifying input semantics, which is the right allocation of effort. It stops short of mentioning the batch size ceiling or cost characteristics that an agent should know before sending a large keyword list.

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 75%, with language, countries, and customerId already documented in the schema. The description reinforces that keywords must be an exact list (no expansion), adding modest semantic value, but says nothing about the 10,000-item limit or how language/countries scope the returned volumes.

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 the resource and enumerates exactly what the tool returns (average monthly searches, 12-month trend, competition, bid range) for an exact keyword list, which is specific and actionable. It does not explicitly name the sibling it differs from (ads_keyword_ideas), though 'exact list of keywords' implicitly contrasts with idea generation.

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 parenthetical example ('the queries a page already ranks for in Search Console') gives a concrete scenario, implying when to reach for this tool. However, it never states when NOT to use it or names ads_keyword_ideas/ads_query as the alternative for discovery-style lookups, so the routing decision is left to inference.

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