move_message

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

With no annotations provided, the description carries the full behavioral disclosure burden. It does this well by revealing the non-obvious consequence: moving a message adds the destination label but may not remove the original label. It does not, however, describe return values or any side effects beyond the label behavior.

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 compact sentences express the operation and its most important caveat without any filler. The main action is front-loaded, and the Gmail label explanation is kept to exactly what the agent needs.

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?

This is a simple mutating tool with no output schema and no annotations, so the description must carry most of the contextual load. It covers the critical label behavior, but it could additionally mention what the result looks like or when the original label is removed. Still, the core decision-relevant context is present.

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?

The schema already provides descriptions for all 4 parameters, giving 100% schema coverage, so the baseline is 3. The description adds a little semantic context by explaining what 'moving' means in terms of destination label vs original label, but it does not detail each parameter's meaning beyond what the schema supplies.

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 uses a specific verb+resource structure ('Move a message to a different mailbox') and immediately clarifies the Gmail label model, which distinguishes this tool from folder-based move operations. It singles out a single message action, which differentiates it from sibling move_messages.

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 context implies this tool is for moving a single message, and the Gmail label caveat gives important situational guidance. However, it does not explicitly say when to use move_message versus move_messages or any other sibling, so the usage guidance is mostly inferred rather than stated.

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