Preview ad

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The sentence 'Does not change the ad' corroborates rather than contradicts that, and the ChatGPT rendering target adds a little context, but there is no disclosure of latency, whether the preview is persisted, or what the render contains.

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?

Two short, front-loaded sentences with no filler; the core purpose leads and the non-mutation caveat follows immediately.

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?

For a single-parameter, no-output-schema tool with annotations present, the description covers purpose and non-mutation adequately, but leaves the sole parameter undefined and gives no hint of what the preview returns.

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?

There is one parameter (ad_id) with 0% schema description coverage, and the description says nothing about it — not its format, not where to obtain it, not whether it refers to an ad in the current account. With the schema silent, the description fails to compensate.

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?

States a specific verb (render/preview) and resource (ad) plus the rendering target (ChatGPT), which cleanly separates it from data-fetching siblings like get_ad or list_ads. An agent can identify the tool's job without opening the schema.

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 says what the tool does but never says when to reach for it over get_ad or list_ads, nor does it name any alternative or precondition (e.g., call before publishing). Usage is only implied.

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