delete_messages

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

Beyond the annotations (destructiveHint=true), the description discloses that deletion is gated behind user confirmation via MCP elicitation and always moves messages to Trash rather than permanently deleting them. This is valuable behavioral context that annotations alone do not provide.

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 two short sentences with the core behavior front-loaded, followed by the important destructive-gating note and a cross-reference to sibling delete tools. Every sentence earns its place, and nothing is redundant.

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 tool with an output schema and fully documented parameters, the description covers purpose, Trash behavior, user-confirmation gating, and relation to sibling delete tools. No critical information needed to call the tool correctly is missing.

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%, and the per-parameter descriptions in the schema already explain account, source_mailbox, message_ids, and the no-op behavior of permanent. The tool description adds no new parameter-level detail, so the 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 states a specific verb and resource: 'Delete messages' with the clarifying behavior 'always moves to the account's Trash mailbox.' This distinguishes it from sibling tools like delete_draft, delete_rule, and delete_mailbox without needing to open schemas.

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 gives clear context that this tool deletes messages and always sends them to Trash, which is enough for an agent to know when to use it. It does not explicitly list exclusions or alternatives, but the tool name and scope make the primary use case unambiguous.

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