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

Annotations already declare readOnlyHint=false and destructiveHint=false, indicating a non-read, non-destructive operation. The description adds useful context about required inputs for create_creative (page_id, image_hash/video_id) and lists CTA enum values, plus bulk support. However, it does not discuss idempotency, return values, or side effects of updates, which would enhance transparency beyond the annotations. No contradiction with annotations.

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 not excessively long, but it is cluttered by listing three actions when only one is the flattened action, and the 'Flattened action: create_ad' aside adds confusion. The structure could be improved by stating the primary action upfront and referencing sibling tools for other actions, making it more concise and clearer.

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?

With 18 parameters, no required parameters, no output schema, and minimal annotations, the tool is high-complexity. The description provides some high-level guidance (CTA options, bulk support, deletion alternative) but omits critical details such as which inputs are necessary for create_ad, how account/auth_account are used, what the return value looks like, and how bulk execution behaves. This is insufficient for an agent to confidently invoke the tool.

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?

The input schema has 0% description coverage, so the description carries the full burden of explaining parameters. It explains image_hash, video_id, page_id, message, call_to_action_type, and the plural bulk fields (page_ids, video_ids, adset_ids, creative_ids, ad_ids). Yet many other parameters (link, name, ad_id, adset_id, status, account, auth_account, creative_id) remain unexplained, leaving significant gaps in parameter understanding.

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 'Create ad creatives and ads (final step to launch)', which identifies the core action. However, it lists multiple actions (create_creative, create_ad, update_ad) that overlap with dedicated sibling tools, creating ambiguity about the tool's specific role. The 'Flattened action: create_ad' note partially resolves this but is not fully clear.

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 provides one explicit alternative ('For destructive delete use meta_ads_creative_delete') but does not explain when to use this tool versus the sibling tools meta_ads_creative_write_create_creative or meta_ads_creative_write_update_ad, even though those actions are listed. The presence of dedicated siblings and the 'flattened action' statement leave usage guidance ambiguous.

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