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 stand alone. It indicates mutation via '[WRITE]' but doesn't disclose idempotency, error states, or whether the dimension must not already exist. Adequate but incomplete.

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 an example, front-loading the key action and context. No wasted words.

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 tool has 4 parameters (2 required), no output schema, and a moderate complexity level. The description covers the core registration action but omits return values, error handling, and prerequisite checks (e.g., parameter must already exist).

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 50% (2 out of 4 parameters have descriptions). The description adds an example but does not explain 'scope' or 'propertyId'. Baseline 3 is appropriate as the description provides minimal additional meaning.

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's purpose: registering an event parameter as a custom dimension in GA4, with a concrete example. It distinguishes itself from sibling tools like ga4_list_custom_dimensions (read) and ga4_create_key_event (different object).

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 explicitly marks it as a WRITE operation and provides an example use case, but lacks explicit guidance on when not to use it or comparisons with alternatives like ga4_create_key_event.

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