google_ads_ad_groups_list

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

The description explicitly marks the tool as read-only, lists return fields (id, name, campaign_id, status, type, cpc_bid_micros, ad_rotation_mode), and explains optional scoping. With no annotations, it carries the full burden and does so well, though could mention potential rate limits or pagination.

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 concise (3 sentences) with front-loaded purpose. Every sentence adds value: first sentence states action and options, second lists returns, third gives usage context. No wasted words.

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?

Given no output schema, the description explains what fields are returned. It also provides usage context and alternatives. For a list tool, this is fully complete.

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% with clear parameter descriptions. The description adds value by explaining the optional nature ('optionally scoped to a single parent campaign and/or filtered by status') and how to omit filters. This goes beyond the schema's basic descriptions.

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 lists ad groups, with optional scoping to campaign and status filtering. It distinguishes itself from sibling tools like create/update and specifies the returned fields, making the purpose unambiguous.

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?

Explicitly says to use this tool to locate an ad_group_id before calling ad_groups.create/update or ads.create, and offers an alternative (ads.list filtered by ad_group_id) when the id is already known. This provides clear when-to-use and when-not-to-use guidance.

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