check_address

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

No annotations are provided, so the description carries the full behavioral disclosure burden. It adds 'Scope: mailbox:read,' indicating a read-only operation, but it does not explain what 'available' means, whether there are side effects, or how errors and responses are structured.

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 front-loaded sentence plus a short scope qualifier. It contains no filler and every element contributes to understanding the tool's 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?

The tool is simple and its only parameter is well documented in the schema, but there is no output schema and the description does not specify the return value or the precise definition of 'available.' This makes the definition adequate but not fully 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?

The input schema already fully documents the single 'address' parameter with an example ('hello@example.com'), so schema coverage is 100%. The description adds no additional parameter meaning beyond the schema, which is the baseline case for this dimension.

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 uses a specific verb ('Check whether') and a specific resource ('mailbox address is available'), which distinguishes it from sibling mailbox operations like get_mailbox or create_mailbox. The 'Scope: mailbox:read' qualifier reinforces that this is an availability predicate rather than a mailbox mutation.

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?

No guidance is provided about when to call this tool versus alternatives such as create_mailbox or get_mailbox. The phrase 'is available' implies a pre-creation check, but the description never states that usage scenario explicitly or mentions any when-not-to-use conditions.

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