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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. 'Without dispatching mail' largely restates readOnlyHint and adds no new behavioral context such as what status output is produced, how long the operation ID stays valid, or failure modes.

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?

A single short sentence with no filler, and the non-dispatching constraint is placed where it reads as the key differentiator. It is efficient, though the terseness borders on cryptic rather than front-loading the actual purpose.

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?

There is no output schema and the description says nothing about what is returned — status values, error states, or whether it blocks until completion. For a status-lookup tool with a single undocumented parameter, the description leaves the agent guessing about the response.

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 0%, so the schema only supplies a pattern and no meaning. The description partially compensates by characterizing the parameter as a 'durable operation ID' that persists from a prior call, but does not explain the format beyond the regex or where the ID comes from.

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 verb 'look up' plus the resource 'operation ID' gives a rough sense of a status/result retrieval, and 'without dispatching mail' implicitly distinguishes it from voidmail_send_once. However, it never plainly states that it returns the status of a previously dispatched send, and 'the same durable operation ID' presupposes context the agent may not have.

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 'without dispatching mail' hints at the contrast with voidmail_send_once (dispatch vs. not), which is implied usage guidance. It does not explicitly say 'use this to poll the result of a send_once call' nor state any preconditions, so the routing signal is only inferable.

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