ga4_create_custom_dimension

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

No annotations are provided, so the description carries the full burden. It indicates a write operation and a confirmation requirement but lacks details on permissions, error handling, or side effects. This is adequate 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?

Two short, front-loaded sentences conveying the core purpose and a critical precondition. No redundant or extraneous content.

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?

For a create tool with a relatively high schema coverage and no output schema, the description covers the essentials but omits return values, error scenarios, or how the custom dimension interacts with other entities. It is adequate but not thorough.

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 86%, so most parameters are already described. The description adds value by emphasizing the confirm parameter as a requirement, which goes beyond the schema's simple boolean description. This compensates for the lack of additional param info.

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 ('Create a custom dimension') and the resource. The GA4 WRITE prefix distinguishes it from read-only or other operations, and siblings like archive, update, list confirm differentiation.

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), guiding when the tool is usable. However, it does not explicitly mention when not to use it or provide alternatives among sibling tools like ga4_archive_custom_dimension.

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