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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so safety is covered. The description contributes the returned-field set (status, type, max CPC, parent campaign), but says nothing about error behavior for unknown ids or account scoping.

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?

A single front-loaded sentence with no filler; the resource, key, and returned fields all appear in one clause.

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?

There is no output schema, so listing the returned fields is genuinely useful and largely fills that gap. An agent has enough to call it correctly; only error/scoping behavior is left implicit.

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 100% and both parameters are documented there, including the optional customer_id default. The description only echoes 'by id' and adds no format, example, or fallback meaning beyond the schema.

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?

States a specific verb and resource ('Get one Google Ads ad group') plus the lookup key ('by id'), which implicitly distinguishes it from google_ads_list_ad_groups. It also names the returned fields, but never explicitly contrasts itself with list_ad_groups or google_ads_query.

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?

Usage is only implied: fetch a single ad group when you already have its id. There is no guidance on when to prefer google_ads_list_ad_groups or google_ads_query instead, and no prerequisites (e.g., requiring a customer_id or connected account) are mentioned.

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