Get Device Metrics

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

With no annotations provided, the description carries the behavioral disclosure burden. The verb 'get' signals a read-only operation, and the GA4 source plus date-range scoping add context. However, it does not disclose pagination, authorization needs, or any other operational behavior, though the output schema helps fill the return-shape gap.

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 front-loaded sentence with no filler, redundancy, or vague qualifiers. Every word contributes meaning about the tool's purpose and scope.

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?

The combination of a 100%-covered schema and an output schema makes the definition mostly complete for invocation: required parameters are documented, the optional dimensions parameter has a clear default, and return shape is covered by the output schema. The main missing piece is usage guidance relative to sibling tools, which is accounted for above.

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 reinforces the date-range parameters ('specific date range') but adds no semantic detail beyond what the input schema already provides for property_id, start_date, end_date, or dimensions.

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 action ('Get'), the resource ('device metrics'), the source ('Google Analytics 4'), and the temporal filter ('specific date range'). It is not a tautology and can be distinguished from siblings by the 'device metrics' focus, though it does not explicitly contrast itself with any sibling.

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 like run_report or get_page_views. There is no mention of exclusions, alternatives, or conditions that would help an agent choose this tool over similar GA4 query tools.

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