Metric Breakdown

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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds behavioral detail by specifying the sorted return format with counts, percentages, bounce rate, and session duration. No contradictions. However, it doesn't discuss pagination behavior or rate limits, which are partially covered by schema.

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 paragraph of 4 sentences, front-loaded with the core purpose. Every sentence adds value—examples, return fields. No wasted words.

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?

Despite 10 parameters and no output schema, the description covers purpose, parameter usage guidance, and return structure. It addresses the tool's complexity well. The only minor gap is a lack of explicit guidance on when to use this vs other get_* tools, but the comprehensive examples implicitly differentiate it.

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% (all parameters have descriptions), so baseline is 3. The description adds value by explaining how the 'parameter' field is used in practice (e.g., 'pathname for top pages') and noting that device_model and app_version only apply to app-type sites. This goes 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?

The description clearly states 'Get metric breakdown by dimension' and provides specific examples (top pages, tech stats, geo, marketing, traffic sources, user flow). This distinguishes it from sibling tools like get_overview or get_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 gives explicit guidance on which dimension values to use for different analysis purposes (e.g., 'Use parameter='pathname' for top pages'). It doesn't explicitly say when not to use this tool, but the level of detail allows the agent to infer appropriate usage.

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