create_responsive_display_ad

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

There is no contradiction with the annotations: readOnlyHint=false matches 'Create.' The description adds a useful precondition (ad group must be in a Display campaign) and detailed input constraints, but it does not describe return values, side effects, validation failures, or asset preconditions. Since the annotations already signal a mutating, non-idempotent operation, the added behavioral context is moderate.

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 tightly organized docstring-style parameter list with no filler. The purpose sentence is front-loaded, and every line in the Args section adds a meaningful constraint or definition. It is appropriately sized for a tool with 12 parameters.

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 12-parameter creation tool with no output schema, the description thoroughly covers all inputs and validation constraints, making it highly actionable. The main gap is the lack of return-value or failure-behavior information (e.g., what happens if the ad group is invalid or asset resource names do not exist), but the parameter coverage is strong enough for correct invocation.

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%, and the description fully compensates. It explains every parameter, including cardinalities (1-5 headlines, 1-5 descriptions), max character lengths (30/90/25), image dimensions (1200x628, 1200x1200), the default status, and the constraint that ad_group_id must be in a Display campaign.

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 opens with a specific verb and object: 'Create a Responsive Display Ad for Display campaigns.' This clearly distinguishes it from sibling tools like create_responsive_search_ad, create_video_ad, and create_demand_gen_ad, which target different ad formats.

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 clear context by stating the tool is for Display campaigns and explicitly warns that the ad_group_id must belong to a Display campaign. It does not explicitly name alternative tools or state when-not-to-use, but the Display campaign scope makes the routing decision fairly unambiguous.

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