list_accounts

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

Beyond the annotations (readOnly, idempotent), the description adds critical behavioral details: 'without credentials', 'Read-only, local, no network call', and 'Returns an empty list if nothing is configured'. These are not redundant with annotations and fully inform the agent about side effects and data source.

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 compact and front-loaded with the core purpose, followed by return structure and usage notes. Every sentence adds value, and there is no extraneous information.

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 zero-parameter tool with an output schema, the description explains the return fields and their meanings, clarifies the default account behavior, and covers how accounts are managed. An agent can call this tool correctly without needing further details.

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?

There are no parameters, so the schema trivially covers everything. The description doesn't need to elaborate on parameters, and the baseline of 4 is appropriate given zero parameters.

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 verb (List), the resource (email accounts), and the scope (configured in GigaMail). It also distinguishes itself from siblings by specifying it deals with account configuration, not messages or events.

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?

It explicitly instructs how to use the output ('Use `id` as account_id in the other tools') and clarifies that accounts are added only via CLI, so there is no alternative tool for this purpose. This gives clear when-to-use context.

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