Create ad post

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

Annotations only say readOnlyHint=false and openWorldHint=true. The description goes further by disclosing the nullcast default, the media_keys/card_uri XOR constraint, the return value, and a critical stop condition on failed creative processing. It could add auth or error details, but it already adds substantial behavioral context.

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 compact and front-loaded: purpose first, then constraints, return value, and safety guardrails. Every sentence earns its place with no redundant filler.

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 6-parameter tool with no output schema and sparse schema descriptions, the description supplies the most critical call semantics: output, next step, XOR constraint, default behavior, and failure handling. It is not fully complete because parameter coverage is uneven, but the core invocation path is well covered.

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?

With only 17% schema description coverage, the description carries much of the parameter-meaning burden. It explains media_keys XOR card_uri and nullcast default true, which are essential. However, as_user_id is left unexplained, and the relationship between media_keys and uploaded media assets is only implied.

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 states a specific verb and resource: 'Create a promoted-only (nullcast) post.' It clarifies what the tool returns ('Returns tweet id') and immediately names the follow-up tool x_ads_create_ad, which differentiates it from the other ad-creation siblings.

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 clear operational guidance: use the returned tweet id with x_ads_create_ad, and stop if the creative failed to upload or process. It would be stronger with explicit comparison to x_ads_create_image_ad or x_ads_create_video_ad, but the context is clear enough to guide correct use.

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