archive_messages

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

With no annotations, the description carries the full burden and does well: it discloses that the move is reversible via move_messages back to inbox, and that confirm_count is a safety gate requiring a prior preview call. It stops short of saying what happens on a count mismatch or whether the Archive folder must pre-exist.

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-loaded with the core action, then the alternative, then the parameter caveat. Every sentence earns its place, though the wrapped confirm_count block reads slightly like a schema note rather than prose.

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 two-parameter mutation tool with no annotations and no output schema, the description covers the action, the sibling routing, reversibility, and the confirm_count contract. Remaining gaps (mismatch error behavior, return value) are minor.

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 coverage is 0%, so the description must compensate, and it does for confirm_count: it defines the equality constraint against the id count and the preview-first protocol. message_ids is only implied by "by id" — no format or limit guidance — which keeps it from a 5.

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 and resource ("Move messages by id to Archive") and immediately distinguishes itself from the sibling archive_matching by explaining that one selects mail itself and needs no ids. 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?

Explicitly names the alternative (archive_matching) and the condition that selects it ("everything older than X" or "everything from Y"). It also prescribes a two-step workflow for confirm_count: call without it first and show the user the list.

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