ga4_create_custom_dimension

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

No annotations are provided, so the description must disclose behavioral traits. It only notes the write nature and the need for confirmation, but omits details on idempotency, side effects, rate limits, or what happens upon creation (e.g., immediate vs. async).

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 concise sentence with a clear prefix, no extraneous information, and front-loads the write context.

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 high schema coverage, the description does not explain the concept of custom dimensions, the role of scope, or the disallowAdsPersonalization parameter. For a tool with 7 parameters and no output schema, this is insufficient.

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 86% (6/7 parameters have descriptions), so the baseline is 3. The description adds no additional parameter meaning beyond what the schema already 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 creates a custom dimension with the prefix '[GA4 WRITE]' indicating a write operation. It distinguishes itself from sibling ga4_update_custom_dimension and ga4_archive_custom_dimension by focusing on creation.

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 specifies prerequisites: GA4_MCP_ENABLE_WRITES=true and confirm=true. However, it does not provide guidance on when to use this tool versus alternatives like ga4_create_custom_metric or when to use which scope.

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