ad_create_preview

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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is known. The description adds nothing beyond that: it does not say whether the preview validates the payload, what it returns (e.g. errors or diff), or that nothing is persisted.

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?

A single short sentence with no filler and the key concept (preview) front-loaded. It is efficient, though its brevity comes at the cost of information rather than achieving compression of useful content.

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 takes a nested typed payload and has an output schema, so return values need not be explained, but for a preview operation in a large family of preview/apply pairs the description should clarify what the preview checks and how it relates to applying changes. One sentence is insufficient here.

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%, including the nested payload with its required fields, so the schema carries parameter meaning. The description adds no additional semantics about profile, adAccountId, or the payload fields, making the baseline 3 appropriate.

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?

"Preview creation of one ad" states a verb and a resource, but it is close to a restatement of the name ad_create_preview and offers no differentiation from the many sibling preview tools (ad_update_preview, ad_delete_preview, ad_group_create_preview). It also leaves what 'preview' actually means (dry-run validation vs. draft creation) undetermined.

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?

There is no guidance on when to call this rather than ad_update_preview, ad_get, or operations_apply. The obvious workflow implication — preview first, then apply — is never stated, so the agent must infer the tool's role in the write pipeline.

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