get_placement_breakdown

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

Description indicates it is a read operation and a hosted endpoint stub, but does not disclose any other behavioral traits such as required permissions, rate limits, or data scope. With no annotations, the description carries the full burden and falls short.

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 with two sentences that front-load the purpose. Every sentence earns its place, though more detail could be added without sacrificing conciseness.

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 7 parameters, no output schema, and no behavioral details, the description leaves significant gaps. It does not explain how to interpret the results or what the nested filters imply. The stub note also reduces completeness for actual usage.

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 all 7 parameters described in the schema. The description does not add new meaning beyond the schema, so baseline 3 is appropriate. It provides context that the tool is for 'performance by ad placement' but no parameter-specific insights.

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?

Description clearly states it retrieves performance by ad placement, with an explicit read hint. It distinguishes from sibling performance tools by specifying 'by ad placement'. However, the note about being an introspection stub may cause confusion about its actual functionality.

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?

No explicit guidance on when to use this tool vs alternatives like get_campaign_performance or get_adgroup_performance. It only mentions it's a hosted endpoint and a stub, but does not provide any context for choosing this tool over similar ones.

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