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

Annotations already carry destructiveHint/idempotentHint, and the description adds substantially beyond them: permanence and unrecoverability, no filter or confirmation step, the fact the inbox address, expiry and allowance are unaffected, and the exact return payload { deleted: N }.

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?

Dense and front-loaded with the destructive nature first, then routing, then side effects, then return shape. Slightly long, and the clause 'whether or not it was returned yet' is awkward, but nearly every sentence carries distinct information.

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?

No output schema exists, but the description supplies the return shape, the side-effect model, and the safety context for a catastrophic irreversible operation. Nothing an agent needs to call this 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?

Zero parameters, so baseline is 4, but the description goes further by explaining the design (no filters, no confirmation) and how the target inbox is resolved via the connection token — semantics an empty schema cannot convey.

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?

States a specific verb+resource with scope ('every email in this inbox at once') and explicitly distinguishes itself from the sibling delete_email. An agent can pick between the two without opening either schema.

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?

Gives explicit when-to-use ('task is finished or to start clean') and a named alternative with its selection condition ('to remove a single email use delete_email instead'), plus a strong call-only-when-you-mean-everything warning.

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