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

Annotations already declare readOnlyHint=false, idempotentHint=true, and destructiveHint=false, so safety is covered structurally. The description restates only that a move happens and adds nothing beyond annotations: no note that the message disappears from the source folder, no cross-domain/mailbox restrictions, no error behavior when the folder is missing.

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?

A single front-loaded sentence with zero filler. It is efficient, but its brevity comes partly from omitting information rather than from disciplined editing.

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 two-parameter mutation with no output schema, the description should still say what the message ID refers to and whether the move is a copy or a relocation. With one of two params undocumented and no behavioral detail beyond annotations, the definition is under-complete.

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% and the description does not compensate. 'another folder' loosely maps to mailboxId, which the schema already documents, while the required `id` parameter is completely undocumented in both schema and description (message ID vs. something else is left to inference).

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?

States a specific verb (moves) and resource (a message) with the destination (another folder). An agent can distinguish it from mail_set_flags, mail_delete, and mail_get, though no sibling is named explicitly.

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?

No guidance on when to use move versus alternatives such as mail_delete followed by mail_send, or versus mail_set_flags. Prerequisites (does the destination folder need to exist? what permissions?) are unstated.

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