create_demand_gen_ad

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

Annotations already indicate the operation is not read-only, not idempotent, and not destructive. The description adds useful context by specifying the ad can serve on multiple channels and includes constraints like character limits and default status, but it does not disclose side effects such as duplicate creation on repeated calls or dependency on previously uploaded assets.

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 well-structured with a clear one-line purpose followed by a compact argument list. Every listed item adds needed parameter context, though some lines simply restate what the schema already provides via titles and types.

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?

The description covers all input parameters and their constraints, which is strong for a 10-parameter creation tool. However, with no output schema, it omits what the tool returns or how errors surface, leaving an agent without expectations for the operation's result.

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?

With 0% schema description coverage, the description carries the full parameter documentation burden. It explains each parameter beyond the raw schema, including counts for headlines/descriptions, character limits, image types, optional CTA, and the status default, which is meaningful added value.

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 clearly states the tool creates a Demand Gen ad and distinguishes it by specifying the channels it serves on (YouTube, Gmail, Discover). This differentiates it from sibling ad creation tools like create_responsive_search_ad and create_video_ad without needing to open any schemas.

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 the tool is for Demand Gen campaigns by requiring the ad group to be in such a campaign and by naming the ad type. However, it does not explicitly state when to prefer this tool over sibling ad creation tools or provide any exclusions or alternative routing.

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