mail_rename_mailbox

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

Beyond annotations (readOnlyHint=false, destructiveHint=false, idempotentHint=true), the description adds a critical behavioral caveat about platform limitations and unreliability, enhancing the agent's understanding of potential errors.

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 sentences with no extraneous content; the first states purpose, the second provides a crucial warning. Information is front-loaded and every sentence adds value.

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 rename operation with three required parameters and no output schema, the description covers the essential operation and a major caveat, though it omits details like return value or idempotency (already in annotations).

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 only 33% schema description coverage (only 'path' is described), the description fails to explain 'accountName' and 'newName,' leaving the agent with little additional meaning beyond the tool name and schema.

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 'Rename an existing mailbox/folder,' specifying the verb 'rename' and the resource 'mailbox/folder,' distinguishing it from siblings like mail_create_mailbox and mail_delete_mailbox.

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 notes unreliability via AppleScript/JXA and advises expecting a PLATFORM_LIMITATION error and fallback to manual renaming, providing guidance on when this tool may fail, though it does not explicitly name alternative tools.

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