create_ad

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

With no annotations, the description carries the transparency burden. It discloses the Dynamic Creative prerequisite and error_subcode 1885998, and mentions cached token behavior for access_token. It lacks details on return values, but the output schema covers that.

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 concise and well-structured: a one-sentence purpose, an Args list, and a Note. Each line provides necessary information without fluff or redundancy.

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 has 8 parameters and no schema descriptions, the description covers all parameters, specifies a failure condition, and explains token fallback. It lacks explicit usage comparisons, but the purpose is clear and the output schema exists for return details.

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%, but the tool description provides detailed, helpful descriptions for every parameter, including the account_id format, an example for tracking_specs, and the default for status. This fully compensates for 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 starts with 'Create a new ad with an existing creative,' which clearly states the verb (create), resource (ad), and a key constraint (existing creative). This distinguishes it from sibling tools like create_ad_creative and create_campaign.

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 implies usage when an existing creative is available, and the Dynamic Creative note adds a prerequisite. However, it does not explicitly compare against alternatives or state when not to use this tool.

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