create_ad

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

With no annotations, the description carries the full burden and discloses key behavior: creation requires a creative object, returns ad_id, and has mutually exclusive file_id/token requirements based on creative type. It does not cover auth, idempotency, or failure modes, but the most decision-relevant behavioral details are present.

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 compact and front-loaded with the purpose, followed by only the essential type-specific instructions and the return value. Every sentence adds operational value with no filler.

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 7 parameters and a nested creative object, the description covers the two creative type branches, the upload_image prerequisite, and the ad_id return value. It does not explain status or idempotency behavior, but the schema provides field constraints and the core calling requirements are sufficiently specified.

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 only 43%, so the description adds meaningful value by specifying how to construct the creative object and when to provide or omit file_id. This compensates for the schema's gaps on the most complex parameter, even though some self-explanatory parameters like ad_account_id and status are not described.

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: 'Create an ad for an ad group,' which clearly distinguishes it from sibling tools like create_ad_group and create_ad_preview. The wording leaves no ambiguity about what is being created.

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?

Provides clear conditional guidance: chat_card requires file_id from upload_image, while product_ad_template requires {{product.*}} tokens and must omit file_id. It does not explicitly route away from alternatives like update_ad or create_ad_preview, but the in-tool branches are clear context.

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