copy-mail-message

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

Annotations already indicate destructiveHint=true. Description adds that it returns a newly created message with a new id, which is useful behavioral context. Does not detail permissions or side effects beyond creation, but sufficient given annotations.

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?

Very concise: two sentences plus a tip. Front-loaded with purpose, then provides key details and alternative. No wasted words.

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 tool with 4 params, nested body object, and no output schema, the description covers core behavior and return value. Lacks explanation of optional params (includeHeaders, excludeResponse) but the schema provides those. Adequate for the operation's simplicity.

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 75% (3 of 4 params described in schema). Description adds meaning by explaining the body's DestinationId can be a folder-id or well-known name, which goes beyond the schema. Other params are already described in schema, so slight improvement over baseline.

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?

Clearly states 'Copy a message to a folder within the user's mailbox.' The verb 'copy' and resource 'message' are specific, and it distinguishes from the sibling 'move-mail-message' by explicitly mentioning an alternative.

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?

Provides explicit alternative: 'For moving instead of copying, use move-mail-message.' Gives guidance on the body format with DestinationId. Does not cover when not to use this tool, but for a simple copy operation it is adequate.

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