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

Beyond the annotations' destructiveHint and readOnlyHint, it discloses that messages and subfolders move with the folder, that the result lists moved children, and the precise refusal behaviors with their rationale. This gives the agent exactly the operational knowledge annotations cannot convey.

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 long, but nearly every sentence carries a distinct operational warning or clarification. It is front-loaded with the core purpose, and the warnings are grouped logically. Slightly verbose, but not padded.

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 destructive folder operation with no output schema, the description covers what moves, what refuses to rename, how to read the refusal, and what the result will show. An agent has enough to invoke it correctly and safely.

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 coverage is 100%, and the description adds extra meaning by clarifying that parent preserves the leaf name and that '/' in newName creates a hierarchy ('Archive/Projects' nests under Archive). It does not add much beyond the schema's property descriptions, hence not 5.

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 names the exact operation ('Rename a folder, or move it under a different parent'), explains the IMAP path semantics, and the refusal list clearly differentiates it from creating or deleting folders. It is unambiguous against sibling tools like create_folder and delete_folder.

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?

It gives clear conditions for the parent-based reparenting path and explicitly lists special folders that will be refused, as well as duplicate names. It stops short of naming alternatives like create_folder, delete_folder, or move_email, so it earns a 4 rather than a 5.

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