Claim mailbox message

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

The annotations only say the operation is not read-only, is idempotent, and not destructive. The description adds substantive behavioral facts: atomicity, a five-minute claim duration, and the same-key acknowledgement requirement. It stops short of detailing expiration/recovery or failure behavior, but goes well beyond the annotations.

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?

Two sentences with no filler: the first states the action and lease, the second states the required follow-up. The most important constraint (acknowledge with the same key) is placed at the end but earned through context.

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 tool with a full schema and output schema, the description provides the behavioral essentials: what is claimed, for how long, and what obligation the caller incurs. Nothing critical is missing for an agent to invoke it correctly in the claim/process/ackworkflow.

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 100%, and both message_id and response_format already have descriptions and defaults/enum values. The tool description adds no parameter-level detail beyond mentioning the claimed message, so the baseline 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?

The description names a specific action ('claim'), a specific resource ('one unread mailbox message'), and adds a concrete constraint ('for five minutes'), so an agent knows exactly what operation is offered. This is clearly distinct from siblings like list_unread, get_message, and ack_message.

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?

It conveys the workflow context: a message should be claimed before processing and then acknowledged with the same API key, which implies when this tool fits relative to siblings. It does not explicitly enumerate alternative tools or exclusions, such as 'for read-only access use get_message', but the claim/ack sequence is sufficiently clear.

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