Create Ad Creative

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

Annotations already indicate this is not read-only or idempotent, and the description confirms the mutating behavior by saying 'Creates.' It also adds that a new creative ID is returned. It does not disclose permissions, validation constraints, or broader side effects, but the annotations lower the burden.

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 starts with a one-sentence purpose and then uses a clean, structured Args list followed by a return-value line. It is appropriately sized for nine parameters, with no redundant filler, though the optional creative-source fields could be grouped more tightly.

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 has nine parameters and no output schema, and the description provides the key creation path plus the returned ID. It does not explain how object_story_id relates to image_url/link_url or what happens when both/both styles of inputs are supplied, which is a meaningful completeness gap for a flexible creation endpoint.

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 33% schema description coverage, the description compensates by providing meaningful labels for most parameters, including the {page_id}_{post_id} format for object_story_id and the ownership relationship for page_id. It omits response_format, though the schema already documents that parameter, and it does not clarify whether image_url and object_story_id are mutually exclusive alternatives.

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 identifies the action and resource: 'Creates an ad creative' from an existing Facebook Page post, which distinguishes it from sibling tools like meta_create_ad and meta_get_ad_creative. However, the 'existing post' framing is narrower than the optional image_url/link_url parameters suggest, so the stated scope is slightly misleading.

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 implies the primary use case: creating an ad creative from a Page post. It does not explicitly state when to prefer this tool over alternatives like meta_upload_ad_image or meta_create_ad, nor does it mention exclusions such as when not to use object_story_id.

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