Add keywords to a Google Ads ad group

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

Annotations indicate readOnlyHint=false and destructiveHint=false, which imply a non-read, non-destructive mutation. The description confirms it adds keywords but does not disclose behavioral traits such as whether existing keywords are preserved (vs replaced), whether duplicates are handled, or if there are limits on the number of keywords. It does not contradict annotations, but the description carries the full burden for mutation behavior and provides minimal insight.

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 a single, short sentence that is efficient and easy to parse. It has no filler, and the key action is front-loaded. However, it is so brief that it misses necessary details, but conciseness itself is not the problem.

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?

Given the tool's moderate complexity (3 parameters, nested objects for keywords, no output schema), the description is incomplete. It does not explain the structure of the 'keywords' parameter, the meaning of 'match_type' (though the schema has enums), or any required context like the ad_group_id. The openWorldHint suggests the API may accept additional properties, but the description does not elaborate on that either.

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 0%, so the description must compensate for explaining parameters. The description does not mention any parameters at all, leaving the agent to rely solely on the schema. It does not clarify that 'keywords' is an array of objects with 'text' and 'match_type', nor that 'customer_id' is optional context. This is a significant gap given the schema's lack of descriptions.

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 the verb 'add' and the resource 'keywords to an existing ad group', which is clear and specific. However, it does not distinguish itself from the sibling tool 'google_ads_add_negative_keywords', which is a related but distinct operation. The title adds clarity but the description itself is minimal.

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 provides no guidance on when to use this tool versus alternatives. For example, it does not mention that this tool is for positive keywords, whereas 'google_ads_add_negative_keywords' is for negative ones. It also does not mention any prerequisites like needing an existing ad group or customer context, which could be inferred from the parameters but is not explicit.

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