gtm_list_accounts

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

With no annotations provided, the description carries the full disclosure burden. It meaningfully reveals the credential-scoped reach ('this credential can reach') and, crucially, interprets the empty-response case as a permission/diagnostic signal rather than an absence of data. This is genuine behavioral context beyond the tool's name.

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 sentences, no wasted words. Purpose is front-loaded, diagnostic guidance follows, and every sentence earns its place.

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?

Complete for a parameterless list tool with an output schema covering the return shape. It covers purpose, call ordering, and empty-result interpretation. Return-format details are properly delegated to the output schema.

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 tool takes zero parameters, so the schema is trivially complete and there is nothing for the description to elaborate. Baseline 4 applies per the rubric for parameter-less tools.

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?

States a specific verb (List) and resource (every Tag Manager account this credential can reach), with clear scope scoping. The 'Tag Manager' qualifier distinguishes it from sibling account-listing tools like ga4_list_accounts and ads_list_accounts, and from gtm_list_containers/gtm_list_workspaces which operate at lower levels.

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?

Provides explicit sequencing guidance ('Call this first') and a concrete interpretation of an empty result (service account not added under GTM > Admin > Account User Management). It doesn't explicitly name alternatives, but the entry-point role is clear from the sibling set where list_containers/list_workspaces presuppose an account.

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