Ad Groups Update Ad Group Cpc Bid

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

Annotations already declare destructiveHint=true and readOnlyHint=false. The description adds the MANUAL_CPC scope and the confirm=true prerequisite, reinforcing a key behavioral condition beyond the annotations. Though 'confirm' is also in the schema, the description's framing emphasizes it as essential to applying the change.

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 two sentences, front-loads the core action, and ends with the key prerequisite. Every word earns its place with no fluff or redundancy.

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 the output schema and annotation coverage, the description captures the core behavior, scope, and prerequisite. It does not detail optional parameters like validate_only or login_customer_id, but those are documented in the schema, and the MANUAL_CPC restriction is the key additional context an agent needs.

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 100%, so all parameters are already documented. The description adds no new parameter semantics beyond referencing 'default max CPC', which maps to default_cpc_bid but adds no format or constraints. Baseline 3 is appropriate because the schema does all the heavy lifting.

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 names a specific verb ('changes'), resource ('ad group'), and field ('default max CPC'), scoped to MANUAL_CPC campaigns. This clearly distinguishes it from siblings like ad_groups_set_ad_group_status or ad_groups_create_ad_group.

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 states the applicable campaign type (MANUAL_CPC) and requires confirm=true, giving clear context for when to use the tool. It does not name explicit alternatives or exclusions, but the condition is sufficient for selection.

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