mail_list_mailboxes

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

Annotations already declare readOnlyHint and idempotentHint. The description adds the useful detail that nested subfolders and unread counts are included, which is behavioral context beyond the structured fields. No contradictions.

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 a single short sentence, front-loading the key action and resource. It is efficient, but could potentially include minimal parameter context without becoming verbose.

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 simple read-only tool with clear annotations, the description covers the main purpose and key inclusions. However, it lacks parameter guidance and usage context, leaving some gaps (e.g., error handling, performance).

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?

With schema description coverage at 0%, the description does not explain the required 'accountName' parameter beyond its name. It fails to specify format, source, or constraints, leaving the agent without guidance on how to populate it.

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 action 'List', the resource 'mailbox/folder tree', and specifies that it includes 'nested subfolders and unread counts'. This distinctly separates it from sibling tools that list drafts, accounts, or signatures.

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 implies the tool is used to view the folder structure, but it does not provide explicit guidance on when to use it versus alternative list tools, nor does it exclude any scenarios. Usage is clear but not differentiated.

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