gads_ad_group_performance

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

Lacking annotations, the description carries the burden but only mentions defaults and optional filters. It does not disclose read-only nature, pagination, or any side effects, though it provides some behavioral hints.

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 a single focused sentence with no redundancy. Every word adds value, stating the core purpose, optional filter, and defaults.

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 and no annotations, the description is too brief. It fails to explain return fields, metrics included, or how 'campaign context' is presented, which is essential for a performance report.

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 has 83% coverage for 6 parameters; description adds little beyond summarizing defaults and the campaign_id filter. Baseline is appropriate as the schema already explains most parameters.

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 returns 'Ad group performance with campaign context' and specifies optional filters and defaults. It distinguishes from siblings like 'gads_campaign_performance' by focusing on ad group level.

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 does not explicitly guide when to use this tool versus alternatives. No when-to-use or when-not-to-use scenarios are mentioned, and no sibling differentiation is provided.

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