Google 広告の検索広告を作成

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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false), so the description only needs to add constraints. It does so well: the default PAUSED status (a safe-create behavior) and the exact validation bounds for headlines and descriptions. It stops short of describing the response or whether the ad is returned/attached.

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?

Compact and front-loaded: the action comes first, then the constraints, then the default status. Every sentence carries content. Slightly dense for non-Japanese readers but no waste.

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?

All 8 parameters are documented in the schema and the key validation rules are restated in the description, but with no output schema the description never says what is returned (e.g., the created ad resource name/id) or what auth/account scoping applies beyond the customer_id default. Adequate but with a clear gap.

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 coverage is 100%, so the baseline is 3. The description earns an extra point by explaining the full-width character-counting rule and its consequence (Japanese limits effectively halved: 15/45), which is the non-obvious part of validating these fields.

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?

States a specific verb+resource (レスポンシブ検索広告を作る) that is immediately distinguishable from siblings like create_campaign, create_ad_group and create_asset_group. An agent knows exactly which ad type is produced.

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?

It never says when to use this tool versus the other creation siblings, nor states prerequisites explicitly. The required ad_group_resource_name implicitly signals an existing ad group is needed, but that is inference, not guidance.

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