set_campaign_target_cpa

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals a critical safety behavior: 'Dry run unless confirm=true.' This tells the agent that the operation is non-destructive by default and requires explicit confirmation to actually apply changes. It does not describe permissions or reversibility, but the dry-run warning is substantial.

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?

Two tight sentences with no filler. The primary action is front-loaded, and the critical dry-run behavior is stated immediately after. Every sentence adds functional value.

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 the essential context: what is set, the unit, the required bidding strategy, and the safety default. An output schema exists, so return-value documentation is not the description's responsibility. It could mention that this modifies an existing campaign rather than creating one, but the tool name and parameters make that clear.

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%, so the description needs to compensate. It explains target_cpa's unit and format ('in account currency, e.g. 9.5') and clarifies the confirm parameter's effect via the dry-run statement. customer_id and campaign_id are not explicitly described, but their purpose is self-evident from the parameter names and the tool name.

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 states a specific action ('Set the target CPA') on a specific resource ('a campaign'), with the exact unit (account currency) and an example value. It also scopes the tool to campaigns using Maximize Conversions, distinguishing it from sibling tools like set_campaign_cpc_ceiling.

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 explicitly identifies the applicable context: campaigns that use Maximize Conversions. It does not explicitly list when not to use it or point to alternatives, but the context is clear enough for an agent to select it appropriately among the siblings.

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