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

No annotations are provided, so the description must carry the full behavioral disclosure. 'Prepare creation' is minimal: it does not say whether this call mutates state, stages a reference, validates the URL, returns a temporary ID, or requires special permissions. This is insufficient for an agent to predict side effects.

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 a single, direct sentence with no filler, and the core verb-object relationship is front-loaded. It is concise, though the brevity comes at the cost of needed behavioral and parameter detail.

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 prepare/confirm tool with no annotations and no output schema, the description is too incomplete: it does not explain what the prepare step returns, whether confirmation is required, or what constraints apply to video_url. The agent must infer critical workflow details from sibling names and external context.

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 only 50%: customer_id is documented in the schema, but video_url has no description. The tool description adds nothing about video_url's expected format (URL vs ID), validation rules, or how it relates to a YouTube asset, leaving a required parameter semantically under-specified.

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 ('prepare creation') and resource ('Google Ads YouTube video asset reference'), and the 'prepare' label helps distinguish it from the sibling google_ads_youtube_asset_confirm. However, it does not explicitly explain what distinguishes this from other prepare/upload tools, so it is clear but not fully differentiated.

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?

There is no guidance about when to use this tool versus alternatives such as google_ads_youtube_asset_confirm, google_ads_asset_upload_prepare, or google_ads_video_upload_prepare. The two-phase prepare/confirm workflow is implied by the name, but the description never states that a confirm step is expected or when this tool is the right choice.

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