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

Annotations already establish idempotent=true, destructive=false, and readOnly=false, and the description adds useful behavioral detail: archived messages are kept, with provider-specific differences (Gmail removes the Inbox label; others move to Archive). It does not cover permissions or return behavior, but the annotations and output schema reduce that burden.

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?

Front-loads the key behavior, follows with the practical use case, and ends with a minimal example. Every sentence earns its place and there is no wasted text.

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 one-parameter tool with annotations and an output schema, the description is nearly complete: it explains archive semantics, provider behavior, and triage usage. The main minor gap is not explicitly routing between archive and other sibling operations like mail_move or mail_trash.

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?

The schema has 100% description coverage for the single message_id parameter, including its format and source. The description’s example reinforces the same information but adds no syntax or constraints beyond the schema, so baseline 3 is appropriate.

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 the specific verb and resource ("Archives a message") and immediately clarifies the outcome: removed from Inbox but kept. This distinguishes archiving from deletion or trashing without needing to name a sibling.

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?

Explicitly says to use it "to clear the Inbox during triage," giving a clear usage context. It does not name alternatives such as mail_move or mail_trash, nor does it state when not to use it, so it falls short of full when/when-not guidance.

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