delete_messages

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

Annotations already indicate destructiveHint=true and idempotentHint=true. The description adds valuable context: deletion always moves to Trash (not permanent), the permanent parameter is currently a no-op, and the operation requires user confirmation. It does not detail behavior for duplicate deletions or error handling, but the added context is significant.

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 extremely concise: two sentences that front-load the core action (delete and move to Trash) and then add critical behavioral notes (destructive gating, similarity to other delete tools). Every sentence earns its place with no redundancy.

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?

Given the tool's complexity (4 parameters, output schema exists), the description effectively covers the key behavioral aspects. It could be more complete by explaining behavior for invalid message IDs or partial failures, but the existence of an output schema reduces the need for such detail. Overall, it provides sufficient context for correct invocation.

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?

Input schema has 100% description coverage for all 4 parameters. The description enhances understanding by revealing that the permanent parameter is reserved and no-op, and that providing both account and source_mailbox together speeds up the operation. This adds meaningful nuance beyond the schema.

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 explicitly states the tool deletes messages and clarifies that it always moves to the account's Trash mailbox, not permanent deletion. It distinguishes itself from sibling delete tools (delete_rule, delete_mailbox, delete_template) by mentioning they match, providing clear purpose and scope.

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 notes that the tool is destructive and gated behind user confirmation, and it matches other delete tools, implying similar usage patterns. However, it does not explicitly guide when to use this tool versus alternatives like update_message or search_messages, nor does it exclude cases where deletion might not be appropriate.

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