List Google Ads accounts

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

Annotations already declare this is a safe read-only, non-destructive open-world operation. The description adds useful behavioral context beyond annotations: it explains MCC account inclusion and documents the meaning of spentLast30Days and plan_status, which matters because there is no output schema.

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 front-loaded with the core action ('Lists every Google Ads account...'), followed by usage and return-field guidance. Every sentence serves a purpose, and there is no redundant restatement of the tool name.

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 zero-parameter list tool with rich read-only annotations but no output schema, the description supplies the key returned-field semantics an agent needs. It does not enumerate the full account object shape, but it covers enough to call and interpret the tool correctly.

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?

There are zero input parameters, so the schema baseline is 4. The description does not need to explain parameters and correctly focuses on return-value semantics instead.

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 gives a specific verb and resource: it lists every Google Ads account the login can reach, including MCC client accounts. It also distinguishes this tool's role by saying 'Start here,' which differentiates it from downstream siblings like switch_account or run_gaql.

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 clearly states when to use the tool ('Start here') and when to surface certain returned fields ('show it when the user picks one'). It does not name explicit exclusions or alternatives, but the starting-point guidance is strong enough for correct selection.

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