update_ad_group

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

With no annotations, the description fully owns behavioral disclosure. It reveals that the tool only drafts (does not apply), that the cpc_bid/target_cpa branches are not live-verified, and that policy rails are re-checked at apply. It also discloses the underlying UpdateAdGroups call is live-proven for status flips. This is exceptionally transparent.

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 focused paragraphs, front-loaded with purpose, and every sentence adds value—parameter semantics, constraints, workflow, and verification status. Nothing is redundant or padded.

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 no annotations, no output schema, and 0% schema description coverage, the description covers return behavior (draft), application flow (confirm_and_apply), parameter constraints, and live-verification status. It supplies everything an agent needs to decide whether and how to call it, with no critical gaps.

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 coverage is 0%, so the description is the only source of parameter meaning. It thoroughly explains target_cpa (introduces an explicit tCPA) and cpc_bid (restricted to MANUAL_BIDDING, silently ignored under Smart Bidding). It also clarifies the interplay between these and the bid strategy, adding far more than the schema provides.

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 it drafts an ad-group update, listing the specific fields (target_cpa, cpc_bid, status) it can modify. It explicitly distinguishes itself from update_keyword_bid by referencing the same guard, and makes clear it returns a draft to be applied later.

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 explains when each parameter is used (target_cpa for MaxConversions, cpc_bid only in MANUAL_BIDDING) and points to confirm_and_apply for the apply step. It implies usage context for ad-group updates versus keyword updates, but does not explicitly enumerate alternative tools or exclusions.

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