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

There are no annotations, so the description carries the full burden of behavioral disclosure. It clearly explains what the tool returns (Audience resources and UserLists with approximate sizes), what those IDs are used for, and what format ad_account_id must take. It does not cover pagination or rate limits, but for a read-only list operation the behavioral disclosure is strong.

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 dense but every sentence earns its place: it defines the two output categories, explains the relationship to campaign creation tools, gives the primary use cases, clarifies the parameter format, and names the sibling tool for the Meta case. No filler or 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?

With no output schema, the description reasonably explains what will be returned: Audience resources, UserLists, and approximate sizes. It also covers the only input parameter and the use cases. It could add more detail about the exact response shape, but the description gives an agent enough context to call the tool correctly and interpret the result at a high level.

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 coverage is 100%, and the schema already documents ad_account_id as a bare 10-digit customer ID with no dashes or act_ prefix. The description mostly repeats this, adding only the helpful hint that the ID comes from adsap_google_list_ad_accounts. This is a small increment above the schema, so the baseline of 3 is appropriate.

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 and resource ('List a Google Ads account's audiences'), and distinguishes two audience types: Audience resources and UserLists. It also ties the result to use in adsap_google_create_pmax_campaign / adsap_google_create_demand_gen_campaign, which differentiates it from siblings like adsap_list_custom_audiences.

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 explicitly says when to use the tool: resolving audience names to IDs before creating PMax or Demand Gen campaigns, or reviewing existing remarketing lists. It also names the Meta equivalent (adsap_list_custom_audiences) as the alternative, leaving no ambiguity about which tool to select.

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