List GTM Variables

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so safety is covered. The description adds the output field details, but doesn't mention pagination or any behavioral caveats. It adds some value beyond annotations but not substantially.

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, front-loaded with the action and resource. No wasted words, perfectly concise.

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 simple list operation with strong annotations and complete schema, the description covers the return content (IDs, names, types) but does not explicitly mention pagination or output format. The optional page_token implies pagination, so it's reasonably complete.

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 100%, with all parameters documented. The description does not add any extra parameter semantics; it merely restates the listing purpose. Baseline 3 is appropriate since the schema already provides the necessary details.

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 (list variables), the resource scope (workspace), and the included fields (IDs, names, types). It distinguishes from gtm_get_variable (single variable) and other list tools (tags, triggers).

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 implies usage for listing variables in a workspace, but provides no explicit guidance on when to use this versus gtm_get_variable or how to handle pagination. No exclusions or alternatives are mentioned.

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