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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the mutation and safety profile are covered structurally. The description adds one genuinely new fact — the change is mirrored 'on the mail server too' — but says nothing about failure modes (e.g. permanently deleted email) or permission requirements.

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?

One sentence, no filler, with the action and destination front-loaded and the server-side caveat as a trailing qualifier. Nothing could be removed without losing 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?

For a one-parameter, non-destructive mutation with full schema coverage and an output schema, the description covers the essential 'what and where'. Only the lack of any pointer to the alternative move_email path keeps it below complete.

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?

There is a single parameter with 100% schema description coverage that already names its source (search_emails or list_to_answer). The description adds no format, constraint or edge-case guidance, so the schema 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?

States a specific verb ('Moves ... back'), the resource (an email) and the destination (the inbox), plus the source states it accepts (archived, filed, trashed). That is enough to distinguish it from archive_email/trash_email/move_email, though no sibling is named explicitly.

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 phrase 'archived, filed or trashed' implies when the tool applies, but there is no explicit 'use this instead of move_email when…' or stated precondition. An agent can infer the use case but not the boundaries against the closely related move_email sibling.

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