mail_accounts

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds a genuinely non-obvious behavioral fact — that passwords are never returned — which tells the agent what NOT to expect in the payload and confirms the read-only, local nature of the call.

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 short sentences, zero waste, with the returned content front-loaded and the caveat placed second. Nothing redundant.

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?

With no parameters, no output schema, and simple annotations, the description covers what an agent needs: what comes back and the key exclusion. It could say slightly more about the shape of 'server settings', but the omission is minor for a no-arg list tool.

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 per the baseline a 4 applies. The description correctly implies a no-argument, whole-list retrieval rather than a filtered one.

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') plus three concrete resources: mailbox IDs, server settings, and local attachment directories. An agent can tell this is a configuration-inspection tool, though it doesn't explicitly differentiate itself from the nearby mail_setup_status sibling.

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?

No guidance on when to call this versus mail_setup, mail_setup_status, or other siblings. The purpose implies inspection of existing configuration, but there is no explicit when-to-use or when-not-to-use statement.

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