discover_keywords

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It does not state whether the operation is read-only, any rate limits, authentication needs, or side effects. It only mentions it uses the Ad Insight GetKeywordIdeas API, which implies a read operation but does not explicitly confirm safety or non-mutating behavior.

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?

The description is two concise sentences with no redundant phrases. The main purpose is stated upfront, followed by essential scope information. Every sentence contributes value and it is easy to parse.

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 tool with two optional parameters and no output schema, the description covers the tool's core purpose and scope, but it omits expected return format, potential errors, or limitations. It is adequate for a basic invocation but leaves some unknowns (e.g., what exactly is returned, how results are structured) that an agent might need.

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?

The schema has 0% description coverage, so the description must compensate. It explains that the tool uses 'seed keywords' and/or 'landing-page URL', directly mapping to the two parameters. However, it does not clarify the format, constraints, or whether one is mandatory (the schema shows both are optional with null defaults), nor does it explain behavior when both are provided. It adds some meaning but not enough for full clarity.

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 clearly states the verb ('discover') and resource ('keyword ideas') and specifies the two input sources (seed keywords and/or landing-page URL) plus the underlying Ad Insight API. It is specific and easily distinguishable from related tools like draft_keywords or get_keyword_forecasts, though it does not explicitly name a sibling it is not.

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 gives useful scope context (location/language/network configured via advertiser settings) and defaults, which helps the agent understand the operating environment. However, it does not provide guidance on when to use this tool versus alternatives like draft_keywords or get_keyword_forecasts, nor any exclusions or prerequisites.

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