get_custom_dimensions_and_metrics

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

Without annotations, the description should disclose behavioral traits like read-only nature, rate limits, or authentication. It only mentions return of custom dimensions and metrics with no details on response format or side effects.

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 short and structured with a purpose statement and an Args section. It is front-loaded and succinct, though it could be slightly more informative without adding verbosity.

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?

While the parameter explanation is sufficient, the description lacks details about the output structure (e.g., field names, array vs object). Given no output schema, the agent might need more context to handle the response correctly.

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?

The description adds meaning to the property_id parameter by specifying accepted formats (number or 'properties/' prefix), which is beyond the schema's bare anyOf type. However, only one parameter exists, so no gap.

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 custom dimensions and metrics for a property, using a specific verb and resource. It distinctively separates from sibling tools like get_account_summaries or run_report.

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 guidance is provided on when to use this tool versus alternatives like get_property_details or list_google_ads_links. It lacks any context about typical use cases or when not to use it.

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