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

With annotations already declaring readOnlyHint=false and destructiveHint=true, the description adds important context beyond those flags: the message leaves the inbox but remains in All Mail and is fully recoverable. This corrects a potentially alarming destructive impression and supplies the confirmation rule, though it does not cover edge cases like already-archived messages or error behavior.

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?

Two tightly written sentences with the core effect front-loaded, followed by the usage constraint. Every sentence earns its place and there is 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?

For a simple two-parameter mutation tool with full schema coverage and annotations, the description covers purpose, reversibility, and confirmation guidance well. Minor gaps around error handling and already-archived behavior are acceptable given the tool's low complexity.

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 schema already documents both account and message_id including the omit-to-try-all-mailboxes behavior. The description adds no parameter-level detail beyond what the schema provides, so the baseline 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 (archive) and resource (one Gmail message), and distinguishes itself from the sibling archive_outlook_message by naming Gmail explicitly. It also clarifies the immediate effect, so an agent can identify the operation without opening the 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?

It gives explicit usage guidance: use only when the user asked for archiving, and confirm first if it is the agent's own suggestion. It does not name alternative tools such as search_gmail_messages or get_gmail_message, so it falls short of full when/when-not/alternatives coverage.

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