Google Ad Manager MCP Server

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

No annotations are provided, so the description carries full burden. It mentions 'Returns report data' and includes a timeout parameter, which adds some behavioral context about asynchronous processing. However, it doesn't disclose important traits like whether this is a read-only operation, what permissions are required, rate limits, error conditions, or the format/structure of the returned data.

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 well-structured with a clear purpose statement followed by detailed parameter documentation. While comprehensive, some information could be more efficiently presented (e.g., the long lists of valid dimensions/metrics). Every sentence serves a purpose, but there's minor room for optimization in the parameter explanations.

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 complexity (11 parameters, no annotations, but has output schema), the description provides strong parameter documentation but lacks behavioral context. The existence of an output schema means the description doesn't need to explain return values, but it should still cover operational aspects like permissions, rate limits, and error handling for a reporting tool of this complexity.

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?

With 0% schema description coverage and 11 parameters, the description compensates excellently. It provides detailed explanations for all parameters including valid values for dimensions, metrics, and date_range_type, examples of JSON array formatting, and clarifies the relationship between date_range_type and the individual date parameters. This adds substantial meaning beyond what the bare schema provides.

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's purpose: 'Run a custom report with specified dimensions and metrics.' This is a specific verb+resource combination. However, it doesn't explicitly distinguish this custom report tool from sibling reporting tools like 'run_delivery_report' and 'run_inventory_report', which prevents a perfect score.

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 provides no guidance on when to use this tool versus alternatives. With sibling tools like 'run_delivery_report' and 'run_inventory_report' available, there's no indication of when a custom report is preferable to these specialized reports or what distinguishes this tool's use case.

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