List Mail Folders

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

The description adds valuable behavioral context beyond the annotations: it mentions the output includes item counts and unread counts, explains that 'total' is the server's own count and trustworthy, and hints at depth behavior. This complements the readOnly/idempotent 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?

The description is three sentences, front-loaded with the main function, and every sentence adds value. It is concise without being under-specified.

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?

Given the presence of an output schema and strong annotations, the description is fairly complete. It covers the purpose, output contents, and a key use case. It doesn't explicitly describe pagination behavior, but the offset parameter description covers that; the note about 'total' adds trustworthiness.

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 description coverage is 75%, so the schema already explains most parameters (depth, offset, parent). The description adds a use case (folder name to FolderId) that implies parent semantics, and the note about 'total' helps interpret pagination. However, it doesn't explain limit/offset beyond what the schema provides.

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 function: 'List mail/calendar folders with their ids, item counts and unread counts.' It also specifies the primary use case of converting folder names to FolderIds for find_emails and move_email, which distinguishes it from sibling tools like get_calendars.

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 explicitly says when to use the tool ('Use it to turn a custom folder name into the FolderId find_emails and move_email accept'), providing clear context. It doesn't explicitly mention alternatives, but given the sibling tools list, the intended use is clear.

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