direct_set_retargeting_bid_modifier

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

With no annotations, the description carries the transparency burden. It explicitly labels the tool as 'WRITE' and notes that allow_write=true is needed, which is useful. But it does not disclose side effects such as whether the adjustment overwrites an existing one, whether it is idempotent, or what errors may occur.

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 single, dense sentence that front-loads the operation type and includes essential context like the write flag and example usage. Every word adds value, with no wasted space.

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 tool has 6 parameters, no output schema, and no annotations, so a fuller description would help. While the description covers the core operation and safety flag, it omits return behavior, dry_run semantics, and project usage details. For a relatively simple write tool, it is adequate but not comprehensive.

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 only 33%, so the description needs to compensate. It names RetargetingConditionId and BidModifier with a range (0–1300) and ties campaign_id to 'on campaign', adding some meaning. However, it does not explain dry_run or project, and retargeting_condition_id is not described beyond its 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 clearly states the operation: 'bidmodifiers.add RetargetingAdjustment on campaign' with a specific resource and action. It also gives a concrete example ('exclude visitors list'), which distinguishes it from more general bid modifier tools like direct_set_bidmodifiers.

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 a clear use case ('Used e.g. exclude visitors list') and implies it is for retargeting adjustments specifically. However, it does not explicitly mention when not to use it or compare it with sibling tools like direct_set_bidmodifiers, so it stops short of full alternative guidance.

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