Wait for a verification code

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

With no annotations, the description carries the behavioral disclosure burden. It discloses that the tool polls until a message arrives, extracts an OTP, and 'times out gracefully.' This gives useful behavioral context beyond the schema. It does not specify the exact return value on timeout or whether the message is consumed, but the core blocking/waiting behavior is clearly conveyed.

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, no filler. The first sentence states the primary action and result, and the second adds the use context and timeout behavior. Everything earns its place.

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 polling tool with no required parametersable to the schema and no output schema, the description covers the main action, return value, ideal timing, and timeout behavior. Minor gaps remain around what happens on timeout and how this relates to the sibling read/list tools, but nothing an agent needs to invoke it successfully is missing.

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%, so all four parameters (from, address, subject, timeout_seconds) are already documented. The description does not add additional parameter-level semantics; it only explains the overall operation. Baseline 3 is appropriate since the schema handles the parameter documentation.

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 states a specific verb ('poll'), a specific resource ('disposable inbox'), and the concrete outcome ('return the verification code (OTP) found in it'). It clearly differentiates this tool from siblings like list_messages and read_message by focusing on waiting for an OTP rather than just retrieving messages.

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 gives a clear trigger context: 'Ideal right after submitting a sign-up form.' This tells an agent when to use the tool. It does not explicitly name alternative siblings or state when not to use it, so it misses a small opportunity to fully disambiguate from list_messages and read_message.

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