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

No annotations are provided, so the description carries the burden. It discloses that the operation is read-only and hot-cached, and that results are 'bounded' (which maps to the limit parameter). It doesn't detail output shape, but the description does disclose key behavioral traits beyond the schema: hot-cached and bounded.

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 sentences with zero filler. The core function is front-loaded, and the behavioral notes (read-only, hot-cached) are useful and concise.

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?

The description is minimal but sufficient for a read-only generation tool with a clear resource and scope. It doesn't explain return shape or how to choose between url vs keywords seeds, but the schema makes both optional, and no output schema is provided. Some agents may need more guidance on how the parameters interact, but the description covers the essentials.

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 14%, so the description must compensate. Although it doesn't explain each of the 7 parameters, it does add meaning: 'bounded' implies the limit parameter, and the tool name plus description clarify that keywords/url are seed inputs for idea generation. The description's context helps interpret the sparse schema.

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 states a specific verb ('generate'), a specific resource ('Google Search keyword ideas'), and clear scope ('for one owned customer'). It also notes the output includes historical metrics. This clearly distinguishes it from sibling tools like keyword_create_prepare/confirm, which are about creating keywords, and insights queries, which are about analytics.

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 says it is for one owned customer, which implies it is not for generating ideas for arbitrary/unowned customers. It does not explicitly name alternatives or exclusions, but the read-only nature and the specific resource make usage context clear. There is no explicit when-not-to-use guidance.

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