create_ad

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

With no annotations provided, the description carries full burden and does well by disclosing: 1) This is a creation/mutation operation (implied by 'Create'), 2) Authentication behavior (access token optional, will use cached), 3) Error conditions (dynamic creative requirements and specific error code). It doesn't mention rate limits or whether the operation is idempotent, but covers the essential behavioral aspects.

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 clear sections (Args, Note) and front-loaded purpose. Every sentence earns its place by providing essential information. It could be slightly more concise by combining some parameter explanations, but overall it's efficient and well-organized.

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 this is a mutation tool with 8 parameters, 0% schema coverage, no annotations, but with an output schema, the description provides excellent coverage of inputs, behavioral constraints, and prerequisites. The output schema will handle return values, so the description appropriately focuses on creation logic and requirements. It could mention sibling relationships more explicitly for completeness.

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 fully compensates by providing: 1) Clear parameter explanations with format requirements (account_id format), 2) Default values (status default: PAUSED), 3) Optional vs required indication, 4) Units (bid_amount in cents), 5) Concrete examples (tracking_specs). This adds substantial value beyond the bare schema.

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 specific action ('Create a new ad') and resource ('with an existing creative'), distinguishing it from sibling tools like create_ad_creative (which creates creatives) and update_ad (which modifies existing ads). The verb+resource combination is precise and unambiguous.

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 about when to use this tool (creating ads with existing creatives) and includes an important note about dynamic creative requirements. However, it doesn't explicitly state when NOT to use it or name specific alternatives like create_ad_creative for when you need to create both ad and creative.

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