create_ad_creative_with_asset_feed

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

With no annotations, the description carries the full burden. It discloses that Meta will auto-combine and optimize text combinations, and requires the parent ad set to be dynamic. However, it does not mention potential rate limits, authentication needs, or any side effects beyond creation. The behavior is adequately described for a creation tool.

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 extremely concise with only two sentences. It leads with 'WRITE:' to signal action, then clearly states the tool's unique behavior and prerequisites. Every word serves a purpose with no redundancy.

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?

Given 12 parameters and no output schema, the description covers the core mechanism (dynamic creative) and a key prerequisite. However, it does not explain what the tool returns (likely a creative object), nor does it address parameters like url_tags or instagram_user_id. It is adequate but not fully comprehensive.

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 low at 42%, but the description adds value by grouping text arrays (bodies, titles, descriptions) and stating the requirement to provide either video_ids or image_hashes. This clarifies the relationship among parameters. However, it does not explain parameters like url_tags or instagram_user_id, leaving some ambiguity.

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 states it creates a DYNAMIC (multi-text) creative using asset_feed_spec, which distinguishes it from the sibling create_ad_creative tool. The verb 'create' and resource 'ad creative' are specific, and the dynamic nature is emphasized.

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?

It explicitly states that the parent ad set MUST have is_dynamic_creative=true, providing a crucial prerequisite. It also instructs to pass arrays of texts and either video or image identifiers, guiding parameter selection. However, it does not explicitly say when to use this vs. non-dynamic creative creation, though the dynamic distinction is implied.

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