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

Annotations already assert readOnlyHint=true and openWorldHint=false, so this definition only has to describe behavior beyond safety. It adds that each folder carries attributes such as \Sent or \Trash, but says nothing about ordering, completeness, whether folders are returned flat or nested, or failure behavior for unconnected accounts.

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?

It is a single front-loaded sentence that states the action, scope, and return content in sequence, with no filler or repetition.

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 a required output schema and readOnly annotations, the definition does not need to explain return values or safety. It covers the essentials for a one-parameter read tool. Only a brief note on ordering or on the connected-account requirement would make it complete.

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 is only one parameter, and the schema documents it at 100% coverage, so the schema carries most of the burden. The phrase 'one connected account' adds context the schema does not: the email must refer to an already-connected account rather than an arbitrary address. That is marginal added value, so the baseline of 3 applies.

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 gives a specific verb (List) and resource (IMAP folders) scoped to 'one connected account' and mentions the returned attributes. It is clearly distinct from email-level siblings such as list_emails or read_email, though it never explicitly distinguishes itself from mailbox_info or list_accounts.

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?

The description relies on the name to imply when to use the tool: enumerate folders of a single account before acting on them. It gives no explicit guidance on when this tool should be preferred over mailbox_info or list_accounts, and it states no exclusions or prerequisites.

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