ga4_list_custom_metrics

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

With no annotations, the description carries the full behavioral disclosure burden. 'List' clearly indicates a read-only operation, but the description does not reveal any additional behavioral traits such as whether archived metrics are included, pagination behavior, or permission requirements. It is adequate for a simple list operation but not rich.

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. Every word ('List', 'custom metrics', 'on a property') contributes to the meaning, making it highly concise and well-structured.

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 tool's simplicity, one optional parameter, and an output schema, the description conveys the core action. However, it lacks parameter semantics and usage guidance, so an agent might not know how to correctly provide property_id or when to choose this tool over a similar list tool. It is minimally viable but has clear gaps.

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 0%, so the description must compensate. It only says 'on a property', which barely adds meaning beyond the parameter title 'Property Id' and the tool name. It does not explain the expected format of property_id, whether it is required, or what happens when it is null, leaving a significant semantic 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 uses the specific verb 'List' with the resource 'custom metrics' and scopes it to 'a property', making the operation unambiguous. It distinguishes from sibling tools like ga4_list_custom_dimensions (different resource) and ga4_create_custom_metric (different action) without needing to open schemas.

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?

There is no guidance about when to use this tool versus alternatives, such as ga4_list_custom_dimensions or ga4_run_report. No exclusions, prerequisites, or context are provided, leaving the agent to infer usage solely from the tool's name and one-line description.

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