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

The annotation already indicates destructiveHint=false and idempotentHint=true, but the description adds concrete behavioral context: the operation moves the email to an archive folder and is reversible, which goes beyond the annotations and clarifies the exact effect on the email.

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 a single, well-structured sentence that is front-loaded with the action and includes a crucial qualifier (reversible). There is no redundancy or unnecessary detail.

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 mutation tool with one parameter and no output schema, the description provides enough context about the operation's effect and safety. It doesn't explain return values, but that is not critical for such a straightforward archiving action.

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 fully covers the single 'id' parameter with a clear description ('Email ID to archive'), and schema description coverage is 100%. The tool description does not add extra parameter context, but the baseline 3 is appropriate because the schema carries the load.

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 clearly states a specific action ('Move an email to the archive folder') with a clear resource (email) and differentiates from sibling tools by emphasizing it is not a deletion. This is a precise verb+resource+outcome statement.

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 provides clear context: use this tool to move an email out of the main inbox into the archive, and it is reversible. It implicitly contrasts with deletion by noting the message is not deleted, offering enough guidance for selection among email-related siblings, though it doesn't explicitly name alternatives.

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