copy_message

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the action but does not disclose whether the source email is preserved, whether message flags are copied, permissions required, or any side effects. This is a significant gap for a mutation tool.

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 a single sentence with no redundant words. It directly communicates the tool's purpose without fluff, making it appropriately concise and well-structured.

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 copy operation with well-documented parameters, the description is adequate but not complete. It lacks context about prerequisites, return values, or behavioral nuances. Given no annotations or output schema, there are clear gaps that could affect an agent's decision to use the tool correctly.

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 input schema has 100% coverage, with descriptions for uid, sourceMailbox, and targetMailbox. The description adds no additional parameter semantics beyond what the schema already provides, so a baseline score of 3 applies.

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 'Copy an email from one mailbox to another' clearly identifies the verb (copy), resource (email), and scope (from one mailbox to another). This distinguishes it from sibling tools like move_message, which implies moving (and thus removing) rather than duplicating.

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 implies a use case (duplicating an email between mailboxes) but does not explicitly state when to use this tool over alternatives. It lacks guidance on conditions like preserving the original, and it doesn't name or exclude sibling tools such as move_message.

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