create_inbox

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

No annotations are provided, so the description carries the full behavioral burden. It does disclose the return payload ('inbox ID and email address'), which is valuable given there is no output schema, but it says nothing about the inbox lifecycle, expiry defaults, tier restrictions, or whether a conflicting slug yields an error.

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 short sentences, purpose front-loaded, with the return contract immediately following. Every sentence earns its place and there is no filler.

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 three-parameter creation tool with no annotations and no output schema, more would help: error behavior on slug collisions, the unstated 60-minute default (only in schema), and what an agent should do with the returned inbox ID afterward. What is present is accurate but thin.

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% with all three optional parameters fully documented, including the slug example, domain default, and TTL tier limit. The description adds no parameter meaning beyond the schema, 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?

States a specific verb and resource ('Create a new disposable email inbox') so an agent can immediately distinguish it from delete_inbox, get_inbox, list_inboxes, and the read/wait siblings. It does not explicitly name or contrast with an alternative, so it falls short of the 5 tier.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives. The word 'disposable' hints at the intended scenario but nothing tells the agent when creating an inbox is the right call versus calling get_inbox or wait_for_email.

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