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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=true. The description adds useful context beyond those annotations: the move also happens on the mail server, no folder is created, and the operation is reversible via restore_to_inbox.

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?

Three short sentences, front-loaded with the primary action and scope. Every sentence carries distinct information: operation, folder constraint, side-effect location, and undo path.

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?

The tool has an output schema and informative annotations, so the description focuses on operational context instead of return values. It gives the agent enough to call the tool correctly: single-email scope, existing-folder requirement, server-side effect, no folder creation, and reversal path.

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 only 50%, so the description compensates for the undocumented 'folder' parameter by saying it must be an existing folder in the same mailbox and referring to list_folders. The 'email_id' parameter is covered by the schema rather than the description, which is acceptable but leaves a minor gap.

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 states a specific verb ('Moves') and resource ('one inbox email to an existing folder'), scoping it to the same mailbox and noting the server-side effect. It distinguishes the operation from archive_email, trash_email, and restore_to_inbox by explicitly naming the undo path.

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 points to list_folders for finding an existing folder, clarifies that no folder is created, and identifies restore_to_inbox as the reverse operation. It does not explicitly compare against archive_email or trash_email, so the when-to-use guidance is strong but not exhaustive.

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