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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered. The description adds a list of returned fields, but with an output schema present that information is largely redundant, leaving little behavioral value beyond the annotations.

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?

Purpose is front-loaded in the first clause, followed by the field list and the parameter note. It is compact with no filler, though the parenthetical field enumeration is somewhat dense and overlaps with the output schema.

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 single-parameter, read-only list tool with an output schema and full annotations, the definition covers purpose, parameter meaning, and default behavior. The only minor omission is that it never points to which sibling tool supplies the account value or mentions pagination, but nothing critical is missing for correct invocation.

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 0%, so the description must carry the single parameter, and it does: 'account = a list_gtm_accounts value or name/id', explaining both the accepted value forms and cross-referencing the sibling tool that produces them. The empty-default behavior is also clarified, which the bare string schema does not convey.

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 states a specific verb and resource ('Lists the containers of a GTM account') and enumerates the returned fields, so the agent knows exactly what this does. It does not explicitly distinguish itself from sibling list tools like list_gtm_accounts or list_gtm_workspaces, but the distinct resource makes the intent unambiguous.

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?

Usage is only implied: the note '(leave empty if there is only one account)' hints at when the parameter can be omitted. There is no explicit when-to-use/when-not guidance and no naming of alternative tools such as list_gtm_accounts to fetch the account value first, so the agent must infer the workflow.

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