list_customers

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

With no annotations, the description must carry the transparency burden. It reveals meaningful behavior: the conditional listing based on customer_id and the scope of 'accessible' accounts. However, it lacks details on authentication, pagination, or the meaning of the 'account' parameter, leaving some behavioral aspects undisclosed.

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 two sentences long, front-loaded with the core purpose, and adds conditional details without redundant information. Every word serves a purpose.

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 description covers the main functionality and the customer_id behavior clearly. However, the 'account' parameter is ambiguous, and the relationship to sibling tools is not addressed. Given the output schema exists, return values are covered, but the parameter ambiguity prevents a higher score.

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 provides no parameter descriptions, and the description only explains customer_id ('If customer_id is provided, lists child accounts under that MCC'). The 'account' parameter is left entirely unexplained, which is a significant gap given the 0% schema coverage. The description does not fully compensate for the missing schema details.

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 the tool's purpose: 'List all accessible Google Ads customer accounts.' It also explains the conditional behavior based on customer_id, listing child accounts under an MCC when provided, which distinguishes it from sibling tools like list_accounts.

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 clear context on when to use the tool (to list customer accounts) and how to use the optional customer_id parameter, but it does not mention alternatives or when not to use it. With sibling list_accounts present, explicit differentiation would improve the score.

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