create_ad_creative

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

No annotations provided, so description carries full burden. It details the two modes and their resulting spec types (asset_feed_spec vs object_story_spec), how Meta displays them, and important constraints like video_id origin and image URL expiration. Minor lack of explanation on other behavioral aspects like error scenarios.

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?

Concise with clear structure: short intro, two paragraphs for modes, and a final paragraph for important notes. Uses bullet-like formatting and bold for emphasis. No redundant sentences.

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?

Output schema exists (not shown) but description doesn't mention return value. Explains modes well but doesn't clarify required params (page_id, link_url) or the significance of other params. Adequate but gaps remain for a tool with 12 parameters.

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 0%, so description adds value for some parameters (video_id, image_url, messages/headlines/descriptions arrays vs strings) but leaves many parameters unexplained (e.g., account_id, call_to_action_type, link_url, page_id, name). Partially compensates but not fully.

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?

Clearly states it creates an ad creative from an ad-account-scoped video. Explains two modes (multi-variant and single-variant) and distinguishes from sibling tools like update_ad and upload_video by referencing flow steps.

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?

Provides explicit guidance on when to use each mode (step 2 vs step 4 of the flow). Warns about video_id source (must be from upload_video, not page-uploaded) and image_url expiration, suggesting get_video_thumbnail as alternative.

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