get_adgroup_performance

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

Annotations already declare readOnlyHint=true, so the tool is understood as a read-only operation. The description adds no further behavioral context beyond stating it is a report. It does not mention authorization, rate limits, or any side effects, providing minimal added value over annotations.

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, efficient sentence that conveys the essential purpose. There is no unnecessary information, and it is well-structured for quick comprehension.

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 the tool has 8 parameters, 100% schema coverage, and an output schema, the description is minimal but covers the core function. However, it lacks details about report contents, required permissions, or how the date parameters interact. The brevity leaves some gaps for an agent to infer.

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%, so the baseline is 3. The description notes that campaignId is required, adding emphasis, but this conflicts with the schema marking it as optional with a null default. No additional parameter semantics are provided beyond what the schema already offers.

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 it provides a performance report by ad group, includes the HTTP method and path, and specifies that campaignId is required. This is specific and distinguishable from sibling tools like get_adgroup or get_campaign_performance.

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 implies usage when an ad group performance report is needed with a campaign ID, but it does not explicitly state when to use this tool over alternatives like get_performance_report or when not to use it. No exclusions or alternatives are mentioned.

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