create_mailbox

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

With no annotations, the description must disclose behavior but only mentions a scope constraint. It does not state whether creation is destructive, what permissions are needed, or what happens if a mailbox already exists, leaving significant gaps.

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 only two sentences, efficient and front-loaded. Every word adds value: the first sentence defines the action and address format, the second adds a key constraint.

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 simple tool with no output schema, the description should hint at return value or error behavior. It mentions a constraint but omits what the tool returns (e.g., mailbox details) and failure cases, leaving some gaps.

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 100%, so the schema already explains both parameters. The description adds the constraint 'One mailbox per project' which provides context beyond the schema, but no additional parameter-level semantics.

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 clearly states the verb 'Create' and the resource 'project-scoped email mailbox' with a specific address format, making the purpose concrete. It distinguishes from sibling tools like get_mailbox or delete_mailbox by focusing solely on creation.

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 description implies a constraint (one mailbox per project) but provides no explicit guidance on when to use versus alternatives or prerequisites. It lacks context about idempotency or conditions under which creation might fail.

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