gtm_create_variable

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only states that a variable is created and gives no detail about required GTM permissions, whether the workspace must be in a certain state, what validation is performed, or what the response contains. The mutation aspect is clear from 'Creates', but significant behavioral context is missing.

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 clear sentence with no fluff. It front-loads the core meaning and is easy to scan. It could offer slightly more detail, but it earns its place without unnecessary length.

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?

There is no output schema, no annotation, and the description does not communicate what type of response to expect or what state changes will occur. For a creation mutation with four required parameters and nested objects, this is under-specified. An agent knows it creates a variable but lacks information about validation, effects on the workspace, or return values.

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?

The schema already documents accountId, containerId, workspaceId, and gives brief descriptions for the variable sub-fields (name, type, parameter). The description adds no parameter meaning beyond what the schema provides. With 75% schema coverage, the schema does most of the work here, so a baseline 3 is appropriate.

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 identifies the action ('Creates') and the resource ('a new variable in a GTM workspace'). While it is somewhat generic, it does distinguish itself from siblings like gtm_update_variable or gtm_delete_variable through the explicit 'Creates a new' wording.

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?

No guidance is provided on when to use this tool versus alternatives such as gtm_create_tag or gtm_create_trigger, nor are prerequisites or special conditions mentioned. The intended context must be inferred from the name and sibling tool list.

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