gtm_variable

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

With no annotations, the description must disclose behavioral traits. It only mentions pagination for 'list' and states the actions. It does not describe mutation effects (e.g., whether remove is hard delete), authentication needs, rate limits, or concurrency control via fingerprint. This leaves significant behavioral gaps.

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 two sentences long, front-loading the core purpose and adding one key detail about pagination. No fluff or redundancy.

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 complexity (9 parameters, nested objects, no output schema), the description is insufficient. It fails to describe return values, error conditions, required action-specific parameters, or how to use fingerprint for optimistic locking. The pagination info is minimal.

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 100%, so the schema already documents all parameters. The description adds no additional semantic meaning beyond what is in the schema. Therefore, it meets the baseline score of 3.

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 explicitly states it performs all GTM variable operations (create, get, list, update, remove, revert) and specifies that list returns up to 20 items per page. This clearly distinguishes it from sibling tools like gtm_tag or gtm_trigger, which operate on different resources.

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 lists the supported actions but does not provide guidance on when to use this tool versus alternatives (e.g., gtm_built_in_variable for built-in variables). Usage context is implied by resource name, but no explicit when-to-use or when-not-to-use instructions are given.

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