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

Annotations already declare destructive=true and idempotent=false, but the description adds real value beyond them: same-mailbox moves create a rename revision, and cross-mailbox moves copy then soft-delete the source without reuploading bytes. The soft-delete detail tells the agent the source is recoverable, which the annotations alone do not 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?

Two sentences, no filler, with the core action stated first and the two move modes immediately following. Every clause earns its place.

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 move tool with a full schema and an output schema, the description covers the essential behavioral distinction between move modes. It omits any mention of failure conditions (e.g., what happens if the destination exists) and does not clarify the relationship between target_path and target_folder, but the output schema and parameter docs carry most of the remaining load.

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 100%, so all seven parameters are already documented in the schema, and the description adds no parameter-level detail. Its "storage reference" phrasing does not map cleanly onto the path/mailbox_id parameters, but it does not mislead about their use.

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 and resource ("Move one file") and differentiates its behavior from siblings like mailbox_file_copy and mailbox_file_rename by explaining the revision/soft-delete semantics. The phrase "by storage reference" is slightly at odds with the path-based parameters, which muddies it a touch.

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 behavioral note about same-mailbox vs cross-mailbox handling implicitly helps an agent choose between move, copy, and rename, but the description never states when to prefer this tool over mailbox_file_copy, mailbox_file_rename, or mailbox_file_reorganize. Usage is implied rather than prescribed.

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