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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds useful domain context (changes staged in a workspace until published), but no behavioral traits beyond that such as auth needs or rate limits.

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 tight sentences: verb+resource front-loaded, followed by domain context and parameter format. No wasted wording, though the return-field parenthetical is somewhat redundant given an output schema exists.

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 two-param read-only list tool that has an output schema, the description is largely sufficient. The only meaningful gap is the undocumented 'account' parameter, which could affect a call where account scoping matters.

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 0%, so the description must compensate. It does a good job on 'container' (accepted formats GTM-XXXX / name / full path, plus the empty-case rule), but the 'account' parameter is entirely undocumented in both schema and description.

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 and resource ('Lists the workspaces of a container') and even enumerates the returned fields (name, workspaceId, path). The resource is distinct from siblings like list_gtm_containers or list_gtm_tags, though no sibling is named explicitly.

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?

Offers one conditional hint ('leave empty if there is only one') that guides the container parameter, and explains the staging model. However, there is no explicit when-to-use-this-vs-alternatives guidance against the many GTM list_* siblings.

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