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

With no annotations, the description carries the burden of behavioral disclosure. It adds useful behavioral context by stating the campaign will be 'paused' and 'atomic,' and clarifies that assets must already exist in the account. However, it does not explain what 'prepare' actually does under the hood, whether it mutates state, or what happens after preparation.

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, tightly written sentence. Every phrase adds value: the action, the campaign type, the paused status, the atomic nature, and the asset source constraint. There is no filler 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 16 parameters with high complexity, no output schema, and no annotations, this one-sentence description is insufficient. It omits what the preparation involves, what the output or receipt will be, whether this is reversible, and what the next required step is. It covers the basic purpose but leaves significant operational details unaddressed.

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 6%, so the description must compensate, but it explains almost nothing about the 16 parameters. The phrase 'using existing account image assets' hints at the asset parameters, and names like budget_micros and bidding_strategy are self-explanatory, but the description does not clarify required parameter relationships, units, or combined usage.

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 uses a specific verb ('Prepare') and clearly identifies the resource ('one atomic, paused standard Performance Max campaign') and the key constraint ('using existing account image assets'). It distinguishes the tool from the confirm counterpart by emphasizing prepare semantics, though it does not explicitly contrast it with google_ads_pmax_create_confirm.

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 gives no explicit guidance about when to use this tool versus its siblings, such as why an agent should choose this over google_ads_pmax_create_confirm or google_ads_campaign_create_prepare. The 'prepare' naming implies a workflow stage but no conditions, alternatives, or exclusions are stated.

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